216 THE STRUCTURE OF MAX 



every other, and his short sight, so far as it involves hereditary 

 tendency, will be handed on by him and will help to make 

 hereditary shortness of sight a widely-spread characteristic in 

 certain classes of society." 



The above sufficiently illustrates the fact that progressive 

 variations are closely connected with retrogressive variations, 

 indeed that to a great extent the former are rendered possible 

 by the latter. If it be true that the adaptation of a creature 

 to its surroundings depends on the process of Natural Selection, 

 we must also consider that Natural Selection is the determining 

 factor in both retrogressive and progressive processes. We have, 

 then, to fall back on the general law of Selection propounded 

 by Charles Darwin, which may be summed up as follows : survival 

 only of the fittest, transmissibility by inheritance, and the gradual 

 improvement of what is advantageous from generation to genera- 

 tion, till the highest possible degree of perfection is reached. 



But wherein lies Man's special " perfection " ? Does such 

 perfection exist, and if so, is it, in comparison with other living 

 beings, as universal as is generally assumed ? Let us look at 

 this matter a little closer. 



There would appear to have been a time when our ancestors 

 were protected against the inclemencies of the weather by a 

 natural covering of hair, and against insects and other injurious 

 influences by an extensive tegumental musculature, when the 

 pinna of the ear, more advantageously disposed than at present, 

 and moved by numerous and powerful muscles, collected the sounds 

 of approaching danger incomparably better than at the present 

 day, and when the sense of smell, probably intensified by Jacobson's 

 organ, was more highly developed than now. Indeed, at a 

 very low stage of phylogenetic development, when the visual organs 

 were placed laterally on the head, and were furnished with a 

 third eyelid, and regulated by more numerous muscles, there may 

 even have been a " third eye " which could perceive what took 

 place above the head (cf. the pineal organ, p. 133). The intestinal 

 tube may have been longer, and thus better suited than at the 

 present day for vegetable diet, the ancestor of Man enjoying at 

 any rate more favourable conditions of existence as a vegetarian 

 than his successor now does (compare also the former greater 

 number of cheek teeth). He may also have had the further advan- 

 tage of not possessing a vermiform process of the ccecum which 

 predisposes to disease, and causes the destruction of a consider- 

 able percentage of his fellows. 



