From A. R. Wallace 8 August 1862
5, Westbourne Grove Terrace, W.
August 8th. 1862
My dear Mr. Darwin
I sincerely trust that your little boy is by this time convalescent,1—& that you are therefore enabled to follow your favourite investigations with a more tranquil mind.
I heard a remark the other day which may not perhaps be new to you, but seemed to me a “fact” if true, in your favour. Mr. Ward2 (I think it was,) a member of the MicroscoScopical Society mentioned as a fact noticed by himself with much surprise, that “the muscular fibres of the whale were no larger than those of the bee”! an excellent indication of community of origin.
While looking at the ostriches the other day at the Gardens3 it occurred to me that they were a case of special difficulty, as, inhabiting an ancient continent, surrounded by numerous enemies how did their wings ever become abortive, & if they did so before the birds had attained their present gigantic size strength & speed, how could they in the transition have maintained their existence? I see Westwood in the “Annals” brings forward the same case,4 arguing that the ostriches shd. have acquired better wings within the historic period;—but as they are now the swiftest of animals they evidently do not want their wings, which in their present state may serve some other trifling purpose in their economy such as fans, or balancers which may have prevented their being reduced to such rudiments as in the Cassowaries’— The difficulty to me seems to be, how if they once had flight could they have lost it, surrounded by swift & powerful carnivora against whom it must have been the only defence.
This probably is all clear to you but I think it is a point you might touch upon as I think the objection will seem a strong one to most people.5
In a day or two I go to Devonshire for a few weeks & hope to lay in a stock of health to enable me to stick to work at my collections during the winter— I begin to find that large collections involve a heavy amount of manual labour which is not very agreeable.6
Present my compliments to Mrs. & Miss Darwin7 & believe me Yours very faithfully | Alfred R. Wallace
C. Darwin Esq.
Muscular fibres of whale no larger than those of bee – evidence of a community of origin.
Problem of the abortive wings of ostrich in relation to conditions of their survival.