76 GENERAL REVIEW OF THE ORCHIDE^. 



The elaborate and interesting account which Mr. Darwin has given | 

 of his own observations and of the experiments he made to satisfy -I 

 himself of the correctness of those observations and the conclusions ' 

 which he drew fi-om them are given in his oft quoted delightful 

 work on F'n'iiHsation of Orchi'h. He also proved that the fertilisation , 

 of many epiphytal orchids must depend on a similar agency, and \ 

 he has described several interesting experiments which he made with 

 flowers grown in the glass-houses of this country. Although we 

 may safely conclude from these experiments and from their failure j 

 to set capsules under cultivation that a vast majority of the 

 epiphytal orchids, especially those with large and showy flowers, in : 

 order to perpetuate themselves by seed must be fertilised by the j 

 aid of some external agent, it by no means follows that in a wild | 

 state all or even a considerable percentage of them are so fertilised, j 

 Actual observation in their native homes can alone determine the ' 

 facts, and this has yet to be undertaken. Almost the only reliable " 

 information at hand has been supplied by Mr. H. 0. Forbes, whose 

 observations were limited to one small locality and to a comparatively ] 

 few species. These observations, however, tend to show that a ! 

 larger number of orchids are self- fertilising than was previously | 

 suspected, and of those for which insect aid is necessary a large 

 proportion of the flowers remain sterile.* 



Mr. ?ovbes' observations were carried on at Kosala, in "West Java, i 

 Of the species with large flowers which possessed no visible means of j 

 self-fertilisation, a plant of Cijmhidium dapelioides bore but one capsule, ! 

 Dendrohiara cr/imenahan had one capsule for every sixty flowers, and ; 

 Calanthe veratrifoUa also about one to every sixty flowers ; Vandas also : 

 had but very few capsules. On the other hand fifteen species are named i 

 that are habitually self-fertilising, including Phaius Bhimei, a geographical | 

 form of the widely dispersed P. iiraiidifollm. From this very restricted 

 range of observations and connecting with it the number of British 

 orchids ascertained by Darwin to be self-fertilising, Mr. Forbes was led I 

 to conclude that the flowers of terrestrial orchids are more liable to self- 1 



Spandaii he devoted all his spare time to botanical pursuits, watching the wild flowers of 

 the district at all seasons and in all weathers with unremitting patience and perseverance. 

 In 1793 he published his curious and valuable work entitled I)as entdeckle Gehehnviss der 

 Ncdur (The discovered Secret of Nature), containing the result of his labours. The little 

 attention given to this work by men of science and the public generally seems to have 

 greatly embittered him, for after its publication he abandoned botanical pursuits altogether, 

 and returned to his former philological studies. He died in 1816. 



* Joum. Linn. Soc. XXI. p. 5S8. 



