P. Pablo Ferrer-Gallego, Inmaculada Ferrando-Pardo, Maja Lazarević
{"title":"(3019) Proposal to conserve the name Hypericum olympicum (Hypericaceae) with a conserved type","authors":"P. Pablo Ferrer-Gallego, Inmaculada Ferrando-Pardo, Maja Lazarević","doi":"10.1002/tax.13152","DOIUrl":null,"url":null,"abstract":"<p>(3019) <b><i>Hypericum olympicum</i></b> L., Sp. Pl.: 784. 1 Mai 1753 [Angiosp.: <i>Guttif</i>. / <i>Hyperic</i>.], nom. cons. prop.</p>\n<p>Typus: Herb. Clifford: 380, <i>Hypericum</i> No. 8 (BM barcode BM000646814), typ. cons. prop.</p>\n<p><i>Hypericum olympicum</i> L. (Sp. Pl.: 784. 1753) (<i>H</i>. sect. <i>Olympia</i> (Spach) Nyman) is a small perennial herb distributed in the Balkan Peninsula (southeastern Serbia, Macedonia, Albania, Bulgaria, Greece [excluding Crete and western Aegean islands] and northwestern Turkey [Jordanov & Kožukharov in Jordanov, Fl. R. P. Bulg. 4: 235, t. 44, fig. 1. 1970; Greuter & al. in Med.-Checklist 3: 270. 1986; Robson & Strid in Strid, Mtn. Fl. Greece 1: 597, fig. 35. 1986; Qosja & al., Fl. Shquip. 2: 296, fig. 550. 1992; Zlatković in Stevanović & Niketić, Fl. Serbia 3: 311–313, 317, t. 53, fig. 1. 2022; POWO, 2023: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:433682-1]). <i>Hypericum olympicum</i> is a variable species, but the variation, though partly geographical, is more or less continuous. In order to make this variation comprehensible, the species was divided into five forms, which remain distinct in cultivation (Robson in Plantsman 1: 193–200. 1980, in Phytotaxa 4: 26. 2010). Moreover, there are several ornamental cultivars of <i>H</i>. <i>olympicum</i> (e.g., ‘Citrinum’, ‘Sulphureum’, ‘Variegatum’) (see https://ecuador.inaturalist.org/taxa/567176-Hypericum-olympicum#cite_note-30).</p>\n<p>Aerial parts of the plant are used in folk medicine for stomach ache, inflamed wounds and cuts (Tuzlacı & al. in Fitoterapia 72: 323–343. 2001), thus its essential oil composition (Gudžić & al. in Flavour Fragr. J. 16: 201–203. 2001; Smelcerovic & al. in Biochem. Syst. Ecol. 35: 99–113. 2007) and antimicrobial properties have been frequently investigated (Ilieva & al. in Plants (Switzerland) 12: 1500. 2023; Kirci & al. in J. Res. Pharm. 27: 2153–2159. 2023).</p>\n<p>Linnaeus (l.c.) described <i>Hypericum olympicum</i> providing a short diagnosis “HYPERICUM floribus trigynis, calycibus acutis, staminibus corolla brevioribus, caule fruticoso” taken from Linnaeus (Hort. Cliff.: 380. 1738) and Van Royen (Fl. Leyd. Prodr.: 473 [not “374”]. 1740), followed by two synonyms: (1) “Hypericum montis olympi” cited from Wheeler [Sir George Wheler 1651–1724] (A Journey into Greece: 222. 1682) and Dillenius (Hort. Eltham.: 182, t. 151, fig. 183. 1732); and (2) “Ascyrum magno flore” cited from Bauhin (Prodr.: 130. 1620; Pinax: 280. 1623), and finally the reference “<i>Burs. XVI</i>: 25”. The protologue also included information about the origin of the species, “<i>Habitat in</i> Pyrenaeis, Olympo”. The references quoted by Linnaeus (Wheeler, l.c.: 221, lib. III, fig. III; Dillenius, l.c.: t. 151, fig. 183) include the illustrations “Hypericon montis Oly[m]pii foliis hursutis” (image available at https://www.alamy.com/stock-image-hypericon-montis-olympi-wheler-george-1682-163330790.html) and “<i>Hyper. mont. Olympi</i> Wheel” (image available at https://bibdigital.rjb.csic.es/viewer/10700/#page=341), respectively, that can be considered as original material used by Linnaeus to describe this species.</p>\n<p>According to Jarvis (Order out of Chaos: 583. 2007), Robson (in Notes Roy. Bot. Gard. Edinburgh 27: 199. 1967) designated as the “lectotype” an original specimen preserved in the Clifford Herbarium at BM (Herb. Clifford: 380, <i>Hypericum</i> 8). However, Robson (l.c. 1967) only mentioned “Subsp. <i>olympicum</i> varies from tall erect large-flowered forms such as that represented by the type specimen from Bithynian Olympus (Uludaǧ) […]” (the ancient Mysian or Bithynian Olympus is a mountain in Bursa Province, Turkey). On the other hand, Robson (l.c. 2010: 24) indicated as “type” of the name: “Type: Turkey, Bursa, ‘crescit in Olympo Asiae monte’, n.d. (fl), <i>Herb. Cliff. 380/8</i> (BM!-holotype)”. This specimen at BM is currently barcoded BM000646814 (image available at https://data.nhm.ac.uk/object/5b6258b8-1d4c-442f-b5e7-ef9ae221658f/1708387200000).</p>\n<p>However, Robson's (l.c. 1967) “type designation” is not effective because the type element is not clearly indicated, as required by <i>ICN</i> Art. 7.11 (Turland & al. in Regnum Veg. 159. 2018). Robson's statement only mentioned the locality, but not the other information, as the herbarium, author, year, etc., and therefore it is impossible to make a direct or indirect relationship between Robson's phrase and the Linnaean original material preserved in the Clifford Herbarium at BM. Robson's (l.c. 2010) “typification” is also not effective according to Art. 7.11 and 9.23 because the typification statement does not include the term “lectotype” (see Art. 9.23; Art. 9.10 does not apply) and the phrase “designated here” (hic designatus) or an equivalent (Art. 7.11).</p>\n<p>In the protologue Linnaeus explicitly cited “<i>Burs</i>. <i>XVI</i>: 25”. This reference is identifiable with a specimen, from Joachim Burser's <i>Hortus Siccus</i> XVI: 25, currently preserved at UPS-BURSER. Thus, even though Robson's (l.c. 1967) “type” was accepted by Jarvis (l.c.), the lectotypification would be unacceptable because Burser's specimen, having been cited by Linnaeus, is a syntype (according to Art. 9.6) and has precedence in lectotype designation over the uncited specimens (see below) and cited illustrations (e.g., Wheeler, l.c.: 221, lib. III, fig. III; Dillenius, l.c.: t. 151. fig. 183) that comprise the remaining original material of the name (Art. 9.12).</p>\n<p>Among the original material of <i>Hypericum olympicum</i>, there are three relevant specimens: (1) the syntype, Herb. Burser XVI: 25 (UPS-BURSER); (2) the Clifford specimen, Herb. Clifford: 380, <i>Hypericum</i> 8 (BM000646814); and (3) a duplicate specimen of Clifford's cultivated material, preserved at LINN, Herb. Linnaeus No. 943.13. The sheet BM000646814 bears a stem with leaves and flowers (image available at https://data.nhm.ac.uk/object/5b6258b8-1d4c-442f-b5e7-ef9ae221658f/1708387200000). The sheet Herb. Linn. No. 943.13 (LINN) bears also a stem with leaves and flowers, and is annotated by Linnaeus “<i>olympicum</i>” and “6” at the base of the sheet, the sheet is also annotated “Hypericum | orientale, flore | ma | gno. T. Cor. 19” (the same annotation as the specimen BM000646814: “Hypericum | orientale, flore | magno. | olympicum”) (image available at https://linnean-online.org/9505/). These latter two specimens (LINN and BM) match the current use and traditional concept of the name <i>H. olympicum</i>, showing diagnostic characters of this species.</p>\n<p>The sheet with the syntype material, Herb. Burser XVI: 25 (UPS-BURSER), bears a plant with leaves and several flowers, with a label annotated as “Ascyron magno flore Baúh. | In Pyrenaeis. | 25”. Juel (in Nova Acta Regiae Soc. Upsal., ser. 4, 5(7): 95. 1923) comments on some aspects related to the origin and identity of this specimen preserved in Burser's herbarium “Burs. XVI (1) 25”: “Bauh. Prodr., 130, gibt von dieser Art an: «In Pyrenaeis D. Burserus hoc, quemadmodum et subsequens, legit.» Seine nächste Art ist H. nummularium. Linné zitiert in Sp. pl. II, 1102, unter <i>Hypericum Ascyron</i> L. den von Bauh. gegebenen Namen, sowie: »Burs. XVI: 25.» Den Fundort »in Pyrenaeis» hat er nach Burser hinzugefügt. Burs:s Exemplar ist, wie frühere Verfasser schon bemerkt haben, nicht <i>H</i>. <i>ascyron</i> L., eine Art die in Westeuropa nicht auftritt, sondern <i>H</i>. <i>Burseri</i> (DC.) Spach. De Candolle nennt in Flore fr. VI, 630, die Bauhin'sche Art <i>H</i>. <i>fimbriatum Burseri</i>, von Spach ist sie dann in Hist. nat. des végétaux V, 397, als eigene Art aufgestellt worden.” Being the sole syntype, it would therefore be the obligate choice for a lectotype (Art. 9.12).</p>\n<p>However, a careful examination of the specimen Herb. Burser XVI: 25 has shown that it does not correspond to the current concept and usage of the name <i>Hypericum olympicum</i>. This specimen can be identified as <i>H</i>. <i>richeri</i> subsp. <i>burseri</i> (DC.) Nyman (based on <i>H</i>. <i>fimbriatum</i> var. <i>burseri</i> DC. in Lamarck & Candolle, Fl. France, ed. 2, 5: 630. 1815; <i>H</i>. sect. <i>Drosocarpium</i> Spach) in having leaves broadly ovate to lanceolate or elliptic, apex obtuse to rounded, base subcordate to rounded; sepals narrowly elliptic to narrowly oblong, acute to subacute, margin glandular-ciliate to glandular-denticulate, petals (10–)15–25 mm long (see, e.g., Robson in Tutin & al., Fl. Europaea 2: 267. 1968; Ramos in Castroviejo & al., Fl. Iberica 3: 170. 1993). <i>Hypericum richeri</i> subsp. <i>burseri</i> is a plant distributed in Spain (Pyrenees, Cantabria) and France (Pyrenees) (Ramos in Trab. Dept. Bot. Univ. Complut. Madrid 12: 56. 1983, l.c. 1993; Tison & al., Fl. France Médit.: 910. 2014). Our identification for this material at UPS-BURSER agrees with Juel's (l.c.) identification.</p>\n<p>Therefore, as the specimen Herb. Burser XVI: 25 (UPS-BURSER) is not in accordance with the current usage of the name <i>Hypericum olympicum</i>, a lectotypification of this name on the Burser specimen in accordance with Art. 9.12 would be nomenclaturally disruptive. Accordingly, to support the continued and well-established use of the name <i>H. olympicum</i>, we propose to conserve the name with a conserved type under Art. 14.9. We here propose the specimen Herb. Clifford: 380, <i>Hypericum</i> 8 (barcode BM000646814) as the conserved type, as already proposed by Robson (l.c. 2010). This specimen shows important diagnostic characters of <i>H. olympicum</i> f. <i>olympicum</i> (e.g., plant usually erect, branched below inflorescence, leaves large, (10–)20–38 × (2–)5–12 mm long, elliptic or elliptic-oblong to lanceolate, acute to subacute, with black intramarginal glands; petals nearly always golden yellow, eglandular, or rarely with a few marginal black glands; see e.g., Robson, l.c. 1967: 199, l.c. 1968: 265, l.c. 2010: 27).</p>\n<p>Rejection of the present proposal would have very undesirable consequences, because the name <i>Hypericum olympicum</i>, which has been unanimously and consistently used by all authors so far, should be applied to <i>H</i>. <i>richeri</i> subsp. <i>burseri</i>, with consequent nomenclatural changes since <i>H. richeri</i> Vill. (Prosp. Hist. Pl. Dauphiné: 44. 1779) is a later name than <i>H. olympicum</i>. Another name would be required for what is now known as <i>H. olympicum</i>, as well as the rest of the infraspecific taxa (see Robson, l.c. 2010: 23–30) included in <i>H</i>. <i>olympicum</i> (i.e., <i>H</i>. <i>o</i>. f. <i>uniflorum</i> Boiss. & Balansa, <i>H</i>. <i>o</i>. f. <i>tenuifolium</i> (D. Jord. & Kož.) N. Robson, <i>H</i>. <i>o</i>. f. <i>macrocalyx</i> (Velen.) N. Robson, and <i>H</i>. <i>o</i>. f. <i>minus</i> Hausskn.).</p>","PeriodicalId":49448,"journal":{"name":"Taxon","volume":"7 1","pages":""},"PeriodicalIF":3.0000,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Taxon","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1002/tax.13152","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"EVOLUTIONARY BIOLOGY","Score":null,"Total":0}
Hypericum olympicum L. (Sp. Pl.: 784. 1753) (H. sect. Olympia (Spach) Nyman) is a small perennial herb distributed in the Balkan Peninsula (southeastern Serbia, Macedonia, Albania, Bulgaria, Greece [excluding Crete and western Aegean islands] and northwestern Turkey [Jordanov & Kožukharov in Jordanov, Fl. R. P. Bulg. 4: 235, t. 44, fig. 1. 1970; Greuter & al. in Med.-Checklist 3: 270. 1986; Robson & Strid in Strid, Mtn. Fl. Greece 1: 597, fig. 35. 1986; Qosja & al., Fl. Shquip. 2: 296, fig. 550. 1992; Zlatković in Stevanović & Niketić, Fl. Serbia 3: 311–313, 317, t. 53, fig. 1. 2022; POWO, 2023: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:433682-1]). Hypericum olympicum is a variable species, but the variation, though partly geographical, is more or less continuous. In order to make this variation comprehensible, the species was divided into five forms, which remain distinct in cultivation (Robson in Plantsman 1: 193–200. 1980, in Phytotaxa 4: 26. 2010). Moreover, there are several ornamental cultivars of H. olympicum (e.g., ‘Citrinum’, ‘Sulphureum’, ‘Variegatum’) (see https://ecuador.inaturalist.org/taxa/567176-Hypericum-olympicum#cite_note-30).
Aerial parts of the plant are used in folk medicine for stomach ache, inflamed wounds and cuts (Tuzlacı & al. in Fitoterapia 72: 323–343. 2001), thus its essential oil composition (Gudžić & al. in Flavour Fragr. J. 16: 201–203. 2001; Smelcerovic & al. in Biochem. Syst. Ecol. 35: 99–113. 2007) and antimicrobial properties have been frequently investigated (Ilieva & al. in Plants (Switzerland) 12: 1500. 2023; Kirci & al. in J. Res. Pharm. 27: 2153–2159. 2023).
Linnaeus (l.c.) described Hypericum olympicum providing a short diagnosis “HYPERICUM floribus trigynis, calycibus acutis, staminibus corolla brevioribus, caule fruticoso” taken from Linnaeus (Hort. Cliff.: 380. 1738) and Van Royen (Fl. Leyd. Prodr.: 473 [not “374”]. 1740), followed by two synonyms: (1) “Hypericum montis olympi” cited from Wheeler [Sir George Wheler 1651–1724] (A Journey into Greece: 222. 1682) and Dillenius (Hort. Eltham.: 182, t. 151, fig. 183. 1732); and (2) “Ascyrum magno flore” cited from Bauhin (Prodr.: 130. 1620; Pinax: 280. 1623), and finally the reference “Burs. XVI: 25”. The protologue also included information about the origin of the species, “Habitat in Pyrenaeis, Olympo”. The references quoted by Linnaeus (Wheeler, l.c.: 221, lib. III, fig. III; Dillenius, l.c.: t. 151, fig. 183) include the illustrations “Hypericon montis Oly[m]pii foliis hursutis” (image available at https://www.alamy.com/stock-image-hypericon-montis-olympi-wheler-george-1682-163330790.html) and “Hyper. mont. Olympi Wheel” (image available at https://bibdigital.rjb.csic.es/viewer/10700/#page=341), respectively, that can be considered as original material used by Linnaeus to describe this species.
According to Jarvis (Order out of Chaos: 583. 2007), Robson (in Notes Roy. Bot. Gard. Edinburgh 27: 199. 1967) designated as the “lectotype” an original specimen preserved in the Clifford Herbarium at BM (Herb. Clifford: 380, Hypericum 8). However, Robson (l.c. 1967) only mentioned “Subsp. olympicum varies from tall erect large-flowered forms such as that represented by the type specimen from Bithynian Olympus (Uludaǧ) […]” (the ancient Mysian or Bithynian Olympus is a mountain in Bursa Province, Turkey). On the other hand, Robson (l.c. 2010: 24) indicated as “type” of the name: “Type: Turkey, Bursa, ‘crescit in Olympo Asiae monte’, n.d. (fl), Herb. Cliff. 380/8 (BM!-holotype)”. This specimen at BM is currently barcoded BM000646814 (image available at https://data.nhm.ac.uk/object/5b6258b8-1d4c-442f-b5e7-ef9ae221658f/1708387200000).
However, Robson's (l.c. 1967) “type designation” is not effective because the type element is not clearly indicated, as required by ICN Art. 7.11 (Turland & al. in Regnum Veg. 159. 2018). Robson's statement only mentioned the locality, but not the other information, as the herbarium, author, year, etc., and therefore it is impossible to make a direct or indirect relationship between Robson's phrase and the Linnaean original material preserved in the Clifford Herbarium at BM. Robson's (l.c. 2010) “typification” is also not effective according to Art. 7.11 and 9.23 because the typification statement does not include the term “lectotype” (see Art. 9.23; Art. 9.10 does not apply) and the phrase “designated here” (hic designatus) or an equivalent (Art. 7.11).
In the protologue Linnaeus explicitly cited “Burs. XVI: 25”. This reference is identifiable with a specimen, from Joachim Burser's Hortus Siccus XVI: 25, currently preserved at UPS-BURSER. Thus, even though Robson's (l.c. 1967) “type” was accepted by Jarvis (l.c.), the lectotypification would be unacceptable because Burser's specimen, having been cited by Linnaeus, is a syntype (according to Art. 9.6) and has precedence in lectotype designation over the uncited specimens (see below) and cited illustrations (e.g., Wheeler, l.c.: 221, lib. III, fig. III; Dillenius, l.c.: t. 151. fig. 183) that comprise the remaining original material of the name (Art. 9.12).
Among the original material of Hypericum olympicum, there are three relevant specimens: (1) the syntype, Herb. Burser XVI: 25 (UPS-BURSER); (2) the Clifford specimen, Herb. Clifford: 380, Hypericum 8 (BM000646814); and (3) a duplicate specimen of Clifford's cultivated material, preserved at LINN, Herb. Linnaeus No. 943.13. The sheet BM000646814 bears a stem with leaves and flowers (image available at https://data.nhm.ac.uk/object/5b6258b8-1d4c-442f-b5e7-ef9ae221658f/1708387200000). The sheet Herb. Linn. No. 943.13 (LINN) bears also a stem with leaves and flowers, and is annotated by Linnaeus “olympicum” and “6” at the base of the sheet, the sheet is also annotated “Hypericum | orientale, flore | ma | gno. T. Cor. 19” (the same annotation as the specimen BM000646814: “Hypericum | orientale, flore | magno. | olympicum”) (image available at https://linnean-online.org/9505/). These latter two specimens (LINN and BM) match the current use and traditional concept of the name H. olympicum, showing diagnostic characters of this species.
The sheet with the syntype material, Herb. Burser XVI: 25 (UPS-BURSER), bears a plant with leaves and several flowers, with a label annotated as “Ascyron magno flore Baúh. | In Pyrenaeis. | 25”. Juel (in Nova Acta Regiae Soc. Upsal., ser. 4, 5(7): 95. 1923) comments on some aspects related to the origin and identity of this specimen preserved in Burser's herbarium “Burs. XVI (1) 25”: “Bauh. Prodr., 130, gibt von dieser Art an: «In Pyrenaeis D. Burserus hoc, quemadmodum et subsequens, legit.» Seine nächste Art ist H. nummularium. Linné zitiert in Sp. pl. II, 1102, unter Hypericum Ascyron L. den von Bauh. gegebenen Namen, sowie: »Burs. XVI: 25.» Den Fundort »in Pyrenaeis» hat er nach Burser hinzugefügt. Burs:s Exemplar ist, wie frühere Verfasser schon bemerkt haben, nicht H. ascyron L., eine Art die in Westeuropa nicht auftritt, sondern H. Burseri (DC.) Spach. De Candolle nennt in Flore fr. VI, 630, die Bauhin'sche Art H. fimbriatum Burseri, von Spach ist sie dann in Hist. nat. des végétaux V, 397, als eigene Art aufgestellt worden.” Being the sole syntype, it would therefore be the obligate choice for a lectotype (Art. 9.12).
However, a careful examination of the specimen Herb. Burser XVI: 25 has shown that it does not correspond to the current concept and usage of the name Hypericum olympicum. This specimen can be identified as H. richeri subsp. burseri (DC.) Nyman (based on H. fimbriatum var. burseri DC. in Lamarck & Candolle, Fl. France, ed. 2, 5: 630. 1815; H. sect. Drosocarpium Spach) in having leaves broadly ovate to lanceolate or elliptic, apex obtuse to rounded, base subcordate to rounded; sepals narrowly elliptic to narrowly oblong, acute to subacute, margin glandular-ciliate to glandular-denticulate, petals (10–)15–25 mm long (see, e.g., Robson in Tutin & al., Fl. Europaea 2: 267. 1968; Ramos in Castroviejo & al., Fl. Iberica 3: 170. 1993). Hypericum richeri subsp. burseri is a plant distributed in Spain (Pyrenees, Cantabria) and France (Pyrenees) (Ramos in Trab. Dept. Bot. Univ. Complut. Madrid 12: 56. 1983, l.c. 1993; Tison & al., Fl. France Médit.: 910. 2014). Our identification for this material at UPS-BURSER agrees with Juel's (l.c.) identification.
Therefore, as the specimen Herb. Burser XVI: 25 (UPS-BURSER) is not in accordance with the current usage of the name Hypericum olympicum, a lectotypification of this name on the Burser specimen in accordance with Art. 9.12 would be nomenclaturally disruptive. Accordingly, to support the continued and well-established use of the name H. olympicum, we propose to conserve the name with a conserved type under Art. 14.9. We here propose the specimen Herb. Clifford: 380, Hypericum 8 (barcode BM000646814) as the conserved type, as already proposed by Robson (l.c. 2010). This specimen shows important diagnostic characters of H. olympicum f. olympicum (e.g., plant usually erect, branched below inflorescence, leaves large, (10–)20–38 × (2–)5–12 mm long, elliptic or elliptic-oblong to lanceolate, acute to subacute, with black intramarginal glands; petals nearly always golden yellow, eglandular, or rarely with a few marginal black glands; see e.g., Robson, l.c. 1967: 199, l.c. 1968: 265, l.c. 2010: 27).
Rejection of the present proposal would have very undesirable consequences, because the name Hypericum olympicum, which has been unanimously and consistently used by all authors so far, should be applied to H. richeri subsp. burseri, with consequent nomenclatural changes since H. richeri Vill. (Prosp. Hist. Pl. Dauphiné: 44. 1779) is a later name than H. olympicum. Another name would be required for what is now known as H. olympicum, as well as the rest of the infraspecific taxa (see Robson, l.c. 2010: 23–30) included in H. olympicum (i.e., H. o. f. uniflorum Boiss. & Balansa, H. o. f. tenuifolium (D. Jord. & Kož.) N. Robson, H. o. f. macrocalyx (Velen.) N. Robson, and H. o. f. minus Hausskn.).
期刊介绍:
TAXON is the bi-monthly journal of the International Association for Plant Taxonomy and is devoted to systematic and evolutionary biology with emphasis on plants and fungi. It is published bimonthly by the International Bureau for Plant Taxonomy and Nomenclature, c/o Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23 Bratislava, SLOVAKIA. Details of page charges are given in the Guidelines for authors. Papers will be reviewed by at least two specialists.