FERTILIZATION OF OECUIDS. 17 



FIELD DAY, JUNE 6th. 



About forty members assembled at Tower, No. 2, and pro- 

 ceeded to the Warren, where the Rev. C. L. Acland, read a 

 paper on 



THE FERTILIZATION OF ORCHIDS. 



I have been asked, on the occasion of this, the third of our pleasant 

 rambles, to read a paper on Orchidaceous plants, or more shortly Orchids. 

 Considering that Sowerby enumerates 44 orchids as natives of the British 

 Islands, and distributes them among 14 genera, it is obvious that an 

 exhaustive account even of our own orchids, would require a treatise 

 rather than a paper. Considering moreover that this family of plants is 

 perhaps without exception the most extraordinary of the whole vegetable 

 world ; that it presents wonders of form, diversities of colour, strange- 

 ness of smell far beyond that shown by any other class of plants that we 

 know, it becomes again evident that I can do my subject but scant justice 

 in the short time I can now ask you to devote to listening to me. I have 

 therefore thought it best to confine my attention to one apparently mi- 

 nute, but really most interesting point connected with the subject of 

 orchidaceous plants, the story namely of their birth, and I will beg your 

 attention while I point out to you the principles on which, from the tiny 

 Dwarf Orchis of our chalk hills to the gigantic Angracum sesquipedale 

 of the Madagascar Forests, the agency of insects is absolutely essential 

 to the fertilization of the plants, and so to the continuance of the difierent 

 species. I may mention, in passing, a peculiarity about the roots of 

 most, if not all, of our perennial orchids. Although perennial, that is, 

 coming up year after year, the plant does not come up from the same 

 root two years in succession. Notice the double bulb of this root. One 

 of these bulbs has given rise to the plant now in my hand, the other is 

 ready to give rise to the plant of next year, last year's bulb has rotted off 

 in the groimd. Each successive year the plant, the same plant observe, 

 epiings from a new root, and as these new roots are always developed in 

 the same direction from the old one, always to the right or always to the 

 left, the plant actually moves from year to year, and at the end of 

 several years is some inches from its original position. Any amount of 

 this kind of work however, so long as one bulb of this year gives but one 

 bulb for next year, could lead to no increase in the number of individual 

 plants. The orchids do not, like the lilies, throw out fresh bulbs in all 

 directions, so that a single plant becomes in turn a patch ; each b«lb 

 produces its one successor and no more, and the chance destruction of an 

 individual plant would at once and for ever lessen by one, the number of 

 individuals in existence but for the propagation by seed, of which I must 

 now speak. 

 C 



