128 Kansas Academy of Science. 



were consciously overused within safe limits, or were con- 

 sciously disused till they dwindled and became vestigial, one's 

 amazement certainly grows that life should have been able in 

 this slow way to have produced such a diversity of parts and 

 organs, all adapted to such a variety of uses and environments. 



Where twenty million years could be used by a long series of 

 life-units in the development of a single organ, such as man's 

 brain, and a succession of one million individuals could each 

 use or disuse the developing parts of this wonderful organ and 

 each transmit to his descendant in the tiniest degree the ten- 

 dency to build the parts used or disused in such a way that 

 they may be used or disused more or less than they had been 

 before, no difficulty should be experienced by any one in under- 

 standing how greatly complicated organs are produced and 

 higher types of animals evolved. 



A myriad of tiny conscious efforts of the same kind may 

 make a habit, and why may not habits persisted in for thou- 

 sands of generations, as geology and biology seem to show — 

 why may not such habits become fixed in life and the tendency 

 to form these habits be transmitted to the following genera- 

 tions? These inherited tendencies may well be termed sub- 

 conscious habits, or semi-instincts, which in millions of years 

 more may become true body-building and body-using instincts 

 independent of direct conscious control. Unfortunate tenden- 

 cies would be ended by natural or artificial selection, as was 

 abundantly demonstrated by Darwin, and useful variations be 

 strengthened by organic selection plus tiny increments of con- 

 scious control continued for millions of years through millions 

 of individuals. 



Many advocates of Mendelianism try to explain the in-^ 

 heritance of body-building and body-using instincts from two 

 lines of ancestors, that of the father and of the mother, by 

 imagining that the sperm and egg chromosomes, when they 

 fuse in synapsis, intermingle their biophores and thus give to 

 the embryo which developes from the fertilized egg a mixture 

 of biophore-corpuscles, some dominant and some recessive in 

 their influence. 



A simpler form of explanation and therefore a better one, 

 a form based on life and its activities and less largely on mat- 

 ter in its inertness and therefore truer, consists in making the 

 fusion in synapsis one of life-instincts and not chiefly one of 

 corpuscles of matter whose arrangement determines, in some 



