254 BIOLOGY: GENERAL AND MEDICAL 



of the female parent, have not the identical composition of those 

 parental biophores. In the process of growth and formation there 

 has been, as it were, a selective process. 



"Owing to the greater affinities, they have attracted and built 

 unto themselves certain side chains derived from the paternal 

 biophores, and from merely attracting them in the first place, 

 they have come to form them actively. According to our con- 

 ception, that is, a side chain, to whatever central ring it is attached, 

 tends to attract ions and radicals of a particular order to itself, so 

 as to reproduce itself in series. This interchange depending upon 

 chemical affinities will not be universal, affecting all the side 

 chains of both paternal and maternal biophores; the newly formed 

 biophores will present an admixture of the two orders; they will 

 occupy definite positions in the nuclear thread and in the chromo- 

 somes derived from that thread. 



"Thus it will happen that in the process of reduction, as in- 

 dicated by the studies upon hybridization, the maturing ovum, or 

 the spermatozoon, may come to contain biophores of paternal or 

 purely maternal origin. The accompanying diagram indicates 

 what we conceive to be the process. 



"Along these lines we believe it is possible to conceive the 

 conveyance of a limited number of biophores in the germ cells, 

 from generation to generation, those biophores under favorable 

 conditions gaining through amphimixis accretions to their proper- 

 ties, under favorable conditions becoming shorn of certain proper- 

 ties, and as a result the individuals developing from these germ 

 cells may show either progressive evolution or devolution." 



REFERENCES. 



HERBERT SPENCER: "Principles of Biology," 1864, N. Y., 1891. 



CHARLES DARWIN: "The Variation of Animals and Plants under 

 Domestication," New York, 1897 



FRANCIS GALTON: " A Theory of Heredity," Jour, of the Anthrop- 

 ological Institute, 1875. "Hereditary Genius," N. Y., 

 1870. " Inquiry into the Human Faculty." 



AUGUST WEISMANN: "The Germ Plasm," N. Y., 1898. 



W. K. BROOKS: "The Laws of Heredity," etc., Baltimore, 1883. 



GREGOR JOHANN MENDEL: "Versuche liber Pflanzenhybriden," 

 1865. Translation published in the Journal of the Royal 

 Horticultural Society of London, 1901-2. 



W. BATESON: "Mendel's Principles of Heredity," Cambridge, 

 1902. 



YVES DELAGE: " L'he're'dite' et les grandes problemes de la 

 biologic," Paris, 1903. 



R. C. PUNNETT: "Mendelism," Cambridge, 1909. 



ROBERT HEATH LOCK: "Recent Progress in the Study of Vari- 

 ation, Heredity and Evolution," London, 1909. 



