vu 



§ 15. It is rather remarkable that, uj:) to this date, not one 

 single genus of Ferns has been discovered which could be 

 said to be exclusively peculiar to this country, while even 

 eighty-eight of the species described in this treatise, or about 

 the half of them only, could claim that privilege. The rest 

 of them are widely diflPused, for we find thirty-one out of the 

 number inhabiting the Mascarenhas (Mauritius and Reunion). 

 Fifteen are found in Europe ; fifteen grow in the West 

 Indies, eleven in New Holland, ten in North America, nine 

 in South America, eight in the Brazils, seven in the East 

 Indies, six in the barren island of Tristan d'Acunha, six in 

 the Canaries and Azores, five at Java, five in Central 

 America, five in the north of Asia, six in the Sandwich 

 Islands, three in North Africa, two in New Zealand and 

 Tasmania, two at Luzon, one in Amboyna, Singapore, Fer- 

 nando Po, China, and Japan. The rare Cyrfomium falcatum, 

 a native of the lastnamed country, has but recently been 

 found by Capt. Espinasse in the forests of British Kaffraria. 



§ 16. Collectors of Ferns should not be satisfied with 

 gathering fertile specimens alone, but secure, in like manner, 

 sterile fronds and young shoots, which often greatly differ 

 from perfect plants in their general aspect. The root-stocks 

 and caudices also are of importance, and ought to be preserved. 



§ 17. To persons who take an interest in the natural history of 

 South African Ferns, a short review of the principal works treat- 

 ing on that topic may be acceptable. Thunberg,* whose writ- 

 ings on the Flora of this country are invaluable, described only 

 thirteen genera and twenty -nine species of Ferns as indigenous. 

 At a later period. Professor de Schlechtendal, encouraged by 

 the examination of the valuable collections brought home by 

 several zealous botanical travellers, and deposited in the Royal 

 Herbarium of Berlin, issued a-work on South African Ferns.f 



*Prodromus Plantarum Capensium, 2d volume. Upsalae, 1800, 8ro., and 

 Flora Capensis, ed. Schultes, Stuttg. 1823, 8vo. 



t Adumbratio Filicum in Proraontorio Bona? Spci provenientium. Part 1-5, 

 Berl. 1825-26, 4to., with 24 engraved plates. 



