56 LECTURES 



the corresponding ones pertain to the physical organiza- 

 tion of man, and no change in their nomenclature is 

 demanded. 



And so we might pass on through the entire anatomy 

 of these several types; but this is not all, for we may 

 bring to bear all our most delicate instruments of pre- 

 cision, and by the aid of the microscope and chemical re- 

 agents reduce the body of a cat, or any of the other forms 

 mentioned, to their ultimate elements, and the very 

 morphological units the cells are the same in a cat as 

 they are in a man; the same in a lemur as they are in an 

 ape; the same in an ape as they are in a cat. 



But, as we are all aware, the matter has not been al- 

 lowed to rest here, for the development of all these types 

 has been carefully studied; and in tracing this back in 

 man. in the cat, in the ape and the rest, we come to a 

 stage in each where the forms presented to us are quite 

 indistinguishable. One cannot help being impressed by 

 the expression of wonder seen in the face of him who, for 

 the first time, views accurate drawings of a tortoise, a 

 chicken, a dog, and a man, at the fourth week of their 

 development. It requires the eye of a thoroughly prac- 

 ticed investigator to tell the one from the other, you may 

 be well assured; for at that stage the tall even offers no 

 distinction and is quite as well developed in man as it is 

 in a dog. Carrying our investigations still further in this 

 matter of development we are led to the fact that all 

 animals have their origin in the simple cell. 



"Moreover," as Huxley tells us, "the investigations of 

 the last three-quarters of a century have proved that 

 similar inquiries, carried out through all the different 

 kinds of animals which are met with in Nature, will lead 

 us, not in one straight series but by many roads, step by 

 step, gradation by gradation, from man at the summit 

 to specks of animated jelly at the bottom of the series. 

 So that the idea of Leibnitz and of Bonnet, that animals 

 form a great scale of being, in which there are a series 

 of gradations from the most complicated form to the 

 lowest and simplest; that idea, though not exactly in the 

 form in which it was propounded by those philosophers, 

 turns out to be substantially correct. More than this, 

 when biologists pursue their investigations into the vege- 

 table world, they find that they can* in the same way, 

 follow cut the structure of the plant, from the most 

 gigantic and complicated trees down through a similar 

 series of gradations until they arrive at specks of ani- 



