Dear Sir

I am extremely sorry to hear of your illness, but hope that you may soon grow stronger.—¹ I enclose M. Perrier’s answer (& he is the highest authority in Europe) that the worm is probably a new sp. of Perichæta.—² You will see that he w^d. be glad to receive from you a collection of the Lumbricidæ³ from Venezuela: if you send them, they had better be sent direct to “M. Prof. E. Perrier Jardin des Plantes, Paris,”—as I am often ill.— Should you observe the ledges on the mountains I sh^d. like much to hear the result, though I do not suppose that I shall ever again publish on the subject.—⁴ Since the appearance of my book I have become doubtful whether I have not exaggerated the importance of worms in the formation of the ledges.— Perhaps they may be due to the sliding down & horizontal cracking of whole of the surface soil.

Pray excuse brevity as I am far from well. | Yours sincerely | Ch. Darwin