DISTINCTIVE CHARACTERISTICS OF MAN. 39 



21. To sum up : The Life of Man essentially consists in the manifestation 

 of Forces of various kinds, of which his Organism is the instrument; and 

 these Forces are developed by the retrograde metamorphosis of the Organic 

 Compounds generated by the instrumentality of the Plant, whereby they 

 ultimately return to the simple binary forms (water, carbonic acid, and am- 

 monia) which serve as the food of plants. Of these organic Compounds, 

 one portion (a) is converted into the tissues of the living body, by a con- 

 structive force which (in so far as it is not supplied by the direct agency of 

 external Heat) is developed by the retrograde metamorphosis of another 

 portion (b] of the food. And whilst the ultimate descent of the first-named 

 portion (a) to the simple condition from which it was originally drawn, be- 

 comes one source of the peculiarly Animal powers the psychical and the 

 motor exerted by the organism, another source of these may be found in a 

 like metamorphosis of a further portion (c) of the food which has never 

 been converted into living tissue. The generative force, as in the Plant, is 

 evidently an expression of the ordinary constructive force; and there seems 

 reason, moreover, for regarding it as a very high expression, its too rapid 

 expenditure producing a peculiarly depressing effect upon the vital power 

 of the organism, which tends to its dissolution. But whilst we find the ulti- 

 mate source of the whole vital power of the organism in the supplies of 

 Food and of Heat which it derives from external sources, it must never be 

 forgotten that its capacity to avail itself of those supplies depends upon its 

 own original constitution ; and that as the form into which the Germ de- 

 velops itself depends upon its own specific endowments, so the particular 

 modification of that form presented by each individual must depend (all 

 external conditions being the same) upon its own individual endowments 

 the differences between these being at present only vaguely referable to ante- 

 cedent conditions of the parental organism. 



CHAPTER II. 



DISTINCTIVE CHARACTERISTICS OF MAN. 



22. IN entering upon the study of that aggregation of phenomena which 

 constitutes the Life of Man, it seems appropriate in the first instance to con- 

 sider his relations to other types of Animal organization ; and to examine 

 what there is in his corporeal and psychical characters, which most distinctly 

 differentiates him from the beings he most nearly resembles. All Zoologists 

 are agreed that his place is at the head of the Mammalian class of the 

 Vertebrate subkingdom ; and that as regards both the general plan of con- 

 formation and the details of anatomical structure, there is a very close 

 approximation between the genus Homo and the semierect tailless Apes 

 belonging to the genera Troglodytes and Plthecus. But there is a consider- 

 able difference of opinion as to the mode in which this relationship should 

 be expressed. By Linnaeus, the Apes and Man were included with Lemurs 

 and Bats in one and the same Order PRIMATES ; and in this non-separation 

 of Man from the Apes, he has been followed by several modern Zoologists 

 of great eminence. On the other hand Blumenbach, who in this was fol- 

 lowed by Cuvier, maintained that the distinctive characters of the genus 



