^ 69 



Notes on the Fertilisation of Orchids. By William Euther- 

 FORD, M.D., President of the Eoyal Medical Society, 

 Kesident Physician Eoyal Infirmary. (Being a portion 

 of a thesis, for which a gold medal was awarded by the 

 Medical Faculty of the University of Edinburgh at the 

 Graduation in 1863.)* 



Mr Darwin, in the introduction to his admirable work on 

 " The Fertilisation of Orchids," states, that his chief reason 

 for writing the work was, " to show that the contrivances 

 by which orchids are fertilised, have for their main object 

 the fertilisation of each flower by the pollen of another 

 flower and to show that, in his " Origin of Species,'' he 

 had good grounds for expressing his belief in what he re- 

 gards as an apparently universal law— viz., " That no her- 

 maphrodite fertilises itself for a perpetuity of generations, 

 an occasional cross with another individual being required." 

 He, moreover, expresses the hope, that his researches may 

 stimulate others to inquire into the habits of our native 

 species. 



During the past summer (1862), T spent some time in the 

 examination of a considerable number of orchids, with a 

 view to ascertain whether or not Mr Darwin's observations 

 were accurate, and the conclusions at which he had arrived 

 correct. The points which I especially wished to test, were, 

 1st, Is insect agency essential for their fertilisation ? 2(i, 

 Is a flower fertilised by its own pollinia, or by those of other 

 flowers ? As regards the first of these, Mr Darwin says, 

 that in every orchis, with the exception of the bee orchis 

 and Gephalanthera grandiflora, insects are required to re- 

 move the pollinia, and apply them to the stigma ; and with 

 regard to tlie second point, he says, — that although in some 

 cases the pollinia may be applied to the stigma of the flower 

 from which they are taken, yet in all they may be — and 

 most generally they are — applied to the stigmas of other 

 flowers ; farther, in some flowers — the marsh Epipactis, for 



* Read before the Botanical Society November 12, 1863. 



