I have read Nos. IV, and V. (156/1. "On our Knowledge of the Causes of the Phenomena of Organic Nature," being six Lectures to Working Men delivered at the Museum of Practical Geology by Prof. Huxley, 1863. These lectures, which were given once a week from November 10th, 1862, onwards, were printed from the notes of Mr. J.A. Mays, a shorthand writer, who asked permission to publish them on his own account; Mr. Huxley stating in a prefatory "Notice" that he had no leisure to revise the lectures.) They are simply perfect. They ought to be largely advertised; but it is very good in me to say so, for I threw down No. IV. with this reflection, "What is the good of writing a thundering big book, when everything is in this green little book, so despicable for its size?" In the name of all that is good and bad, I may as well shut up shop altogether. You put capitally and most simply and clearly the relation of animals and plants to each other at page 122. Be careful about Fantails: their tail-feathers are fixed in a radiating position, but they can depress and elevate them. I remember in a pigeon-book seeing withering contempt expressed at some naturalist for not knowing this important point! Page 111 (156/2. The reference is to the original little green paper books in which the lectures first appeared; the paging in the bound volume dated 1863 is slightly different. The passage here is, "...If you couple a male and female hybrid...the result is that in ninety-nine cases out of a hundred you will get no offspring at all." Darwin maintains elsewhere that Huxley, from not knowing the botanical evidence, made too much of this point. See "Life and Letters," II., page 384.) seems a little too strong--viz., ninety-nine out of a hundred, unless you except plants.