Zoology as Related to Evolution. 215 



finds shining out as a vein of gold from the dark strata of 

 paleontology and from the forms even of the most monster- 

 like brutes. 



Not to dwell on their work in making the earth's conti- 

 nents and soils, and in elaborating its crude inorganic ele- 

 ments into nourishing foods, the why of their existence, of 

 their forms in the past, and of the whole process of their 

 growth from moner up to man, is to be found in Darwin's 

 doctrines of variation and heredity in their acquisition of 

 organs and qualities by variation step by step in the only envi- 

 ronment that was fitted for their production, and then in the 

 transmission of them by inheritance from species to species 

 up into higher surroundings and finer shapes, and at last into 

 their existing completeness. Animals have been not merely 

 the lineal ancestors, but beyond this the necessary makers of 

 humanity, the only possible builders not only of man's dwell- 

 ing place and man's food, but of man himself. Nature's 

 method of phylogenic growth, made inevitable apparently 

 by her own inherent laws, has been herself to push forward 

 an organ a little way and then to set its recipients to using 

 it with their own will-power over and over, till at last, like 

 the beating of our hearts, it unconsciously did itself, and 

 then to employ her vitality, released from this work, in push- 

 ing out still another organ on which the process was repeat- 

 ed ; and so on, the gain of one generation being transferred 

 by inheritance to the next, a thing impossible, you see, 

 under the old idea of species as independent creations. The 

 uniting of its four great elements, in some respects the most 

 refractory of Nature, into the original protoplasmic mortar 

 out of which all animals are built up, had probably to be 

 done millions of times by its low amoebic forms before they 

 got the habit of staying united ; and every step of the won- 

 derful organization and functioning to which it has now 

 arrived in humanity has been taken by having myriads 

 of animals along the way go through with its various opera- 

 tions of digestion, respiration, nerve-action, sense-percep- 

 tion, blood-circulation and the like, again and again till' 

 what at first was direct effort done by giving their minds 

 to it became at last involuntary action, done without a 

 thought. Man is indeed a bundle of habits, and a bundle 

 formed not only by himself, but by all the multitudes of 

 creatures that are in the lines of his descent back to the 

 first amoeba that ever ate its bit of brother slime. A few 

 years ago, as a German naturalist was watching the hatching 



