Thanks RT for his letter and MS.

Is astonished by the different forms of orchids he describes.

Urges RT to describe and experiment with two or three of the more distinct genera.

"I believe, or am inclined to believe in one or very few primordial forms, from community of structure and early embryonic resemblances in each great class."

CD thinks that he believes in as much migration as AdeC, only he does not believe nearly so much in continental extensions. CD also believes more in modification in form though he suspects the difference is not so great.

Thanks AdeC for information on melons, oranges,

and Swiss lake-habitation discoveries.

CD is almost tired of his book on variation under domestication, for his knowledge is insufficient to treat the plant part well, but he has done so much that he will finish it.