Sir.

I think you do not mention the genus Comparettia in your excellent work on Fertilization in Orchids etc. I have just had the opportunity of examining the structure of C. falcata, and find that it is frequently self-fertilizing¹   Out of 5 flowers, there were not less than 4 with the ovaries well fertilised. and in the other flower, I found the pollen masses upon the stigma. It seems that when the stigma is ready the anther ruptures from the base upwards, and by the least shake or disturbance the heavy pollen masses are dislodged, and, the rostellum being very narrow and beak-like, there is nothing to prevent it from falling upon the stigma. the caudicles, not being able to sustain their weight,; the flexibility of the latter I consider is very important to effect cross-fertilization; but, that, cross-fertilisation may be brought about the pollen mass must be removed before the complete rupture of the anther has taken place. The naked disk at the end of the rostellum is very viscid, and firmly attaches itself to any intruder in about 30 seconds; so firm in fact, that I could not blow it of. if the caudicle remained such when drawn, it would not place the pollen against the stigma, but owing to their bending the stigma is reached.²

I should be glad if you would correct any errors I may have made.. and you are at perfect liberty to copy the rough sketches, and, if you will kindly return. the originals,³ as that is what I may require, you will oblige | faithfully | your’s | J. T. Riches

C. Darwin Esq^r.