I rejoice that you have made a beginning, and such a beginning--for the more I think about it the more important it seems to me that somebody should think out into a connected system the loose notions that are floating about more or less distinctly in all the best minds. It seems as if all the thoughts in what you have written were my own, and yet I am conscious of the enormous difference your presentation of them makes in my intellectual state. One is thought in the state of hemp yarn, and the other in the state of rope. Work away, then, excellent rope-maker, and make us more ropes to hold on against the devil and the parsons. For myself I am absorbed in dogs--gone to the dogs in fact--having been occupied in dissecting them for the last fortnight. You do not say how your health is. Ever yours faithfully, T.H. Huxley. September 19, 1860. My dear Spencer, You will forgive the delay which has occurred in forwarding your proof when I tell you that we have lost our poor little son, our pet and hope. You who knew him well, and know how his mother's heart and mine were wrapped up in him, will understand how great is our affliction. He was attacked with a bad form of scarlet fever on Thursday night, and on Saturday night effusion on the brain set in suddenly and carried him off in a couple of hours. Jessie was taken ill on Friday, but has had the disease quite lightly, and is doing well. The baby has escaped. So end many hopes and plans--sadly enough, and yet not altogether bitterly. For as the little fellow was our greatest joy so is the recollection of him an enduring consolation. It is a heavy payment, but I would buy the four years of him again at the same price. My wife bears up bravely. I have read your proofs at intervals, and you must not suppose they have troubled me. On the contrary they were at times the only things I could attend to. I agree in the spirit of the whole perfectly. On some matters of detail I had doubts which I am not at present clear-headed enough to think out. The only thing I object to in toto is the illustration which I have marked at page 24. It is physically impossible that a bird's air-cells should be DISTENDED with air during flight, unless the structure of the parts is in reality different from anything which anatomists at present know. Blowing into the trachea is not to the point. A bird cannot blow into its own trachea, and it has no mechanism for performing a corresponding action.