92 UNIVERSAL EVOLUTION 



and simply determine what shall survive, and what 

 shall die. If the species is formed at once by mutation, 

 it may be the result of some combination of conditions, 

 both internal and external, that is not of sufficient 

 permanence, in time and space both, to insure its long 

 survival. Natural selection then annihilates it, as soon 

 as the conditions of its origin are modified. It seems 

 plausible that sudden "sports" or jumps of this kind, 

 made in domesticity, are apt to be ephemeral. But a 

 species in the wild state that has developed gradually, 

 has had time to be tested in a sufficiently widespread 

 variability of climate, soil, in abundant, or scant sus- 

 tentation, in calm and storm, to be pretty certain of 

 permanence. 



VARIATIONS ARE OF FORM. It must be understood the 

 variations upon which natural selection operates are not 

 fanciful, unseen, or artificial changes in the cells only 

 of the body, or internal organs, or in the psychical de- 

 vice, giving the individual a life separated in its 

 sources from the old form, a new way of develop- 

 ment of the germ cell, nor do they change any per- 

 sistent law of nature relative to man's relation to his 

 environment. They are plain common sense changes 

 of form, color, size, or in the neural arcs, by which a 

 new nerve is added, or a new connection is made, by 

 which the speed is increased, or a greater tendency to 

 caution, or a keener use of the peripheral sense is in- 

 duced. If an increase occur in the size of a muscle,, or 

 a bone, the legs of a growing animal shortened, or his 

 body made more compact, or more power put in the 

 digestive surface, or in the thickness of the skin, and 

 the density of the hair on the skin, to better withstand 

 cold and rain, it is readily seen that all these are of bene- 

 fit to the individual ; and if future variations of the same 



