102 The Insides and the Wordings of Living Things 



ory other than the supposition that an inscrutable intel- 

 Hgence placed it in our bodies for the purpose of blinding 

 us. While it cleans the eyeball and shuts out light in the 

 lower classes of vertebrates, it does not interfere with vision. 

 Unless we deliberately shut our eyes, we can see past this and 

 hope to understand. 



Robert Wiedersheim, a German professor of human 

 anatomy, found nearly two hundred structures that have no 

 relation at all to the life or effectiveness of the organism but 

 that correspond to structures occurring in a functional state 

 in other animals, especially primates. It must be admitted 

 that in many cases the student will report ** no function " 

 when he is warranted only in saying " I can find no func- 

 tion." There are indeed numerous structures in the human 

 body having very significant functions that have come to be 

 recognized, as a result of animal experimentation and clinical 

 studies, only within a generation. Among these is the 

 pineal gland lying between the two halves of the brain near 

 the optic lobes. This structure is smaller in the adult than 

 it is in the embryo, and is larger in some other mammals than 

 it is in man. It is not, however, a rudimentary or vestigial 

 structure, in the sense in which this term has been used by 

 biologists, regardless of its history in the various classes of 

 backboned animals, since it has in the human race a well 

 defined function. In the same way an earlier generation of 

 scientists speculated regarding the origin and meaning of the 

 pituitary gland and the thymus, whereas today we are find- 

 ing out a great deal about these structures in terms of their 

 relations to the growth and development of the body. It 

 is nevertheless true that there remain structures whose ho- 

 mologies are perfectly clear and whose presence in one or an- 

 other group of plants or animals cannot, on any theory of 

 clear-cut purposeful creation, be accounted for. 



Reduced Organs 



Other animals also carry these vestiges about for what- 

 ever they may mean. Insects that live on ocean islands are 



