126 



PHARMACEUTICAL BACTERIOLOGY 



reduced to a minimum (a, b, c, d). In the gametic union these properties 

 would be combined in the zygote, at least we can assume that such might 

 be the case. In the cell septations which would result from this zygotfe 

 the properties (inherited) of the two gametes might appear in the daughter 

 cells in sixteen possible combinations and it is readily comprehensible 

 how and why some of the combinations would be more suitably adapted 

 to the environment than others and these would secure the survivaltof the 

 race or species. 



Fig. 44. — Illustrating the redistribution of hereditary properties after the fusion 

 of the female gamete (I) and the male gamete (II), forming the zygote (Z), which 

 upon starting a new septating cycle gives rise to cells in which the original properties 

 of the two gametes (A, B, C, D, and a, b, c, d) may be rearranged in sixteen different 

 combinations. (Adapted from the chart by Wilson.) 



The investigations of Biitschli, Calkins, Hertwig, Jennings, Maupas 

 and others, led to the conclusion that the union of gametes in sexual repro- 

 duction had the effect of adapting a few out of many to the environment, 

 through restoration or augmentation or restimulation of weakened ac- 

 tivities. The somatic existence of single-celled animals and of the many- 

 celled animals, has occasioned much discussion. It has been customary to 

 speak of single-celled animals such as the paramecia, the amebas, etc., as 

 endowed with eternal life, barring accidents, and that the complex organ- 

 isms as man, for example, is doomed to suffer an unavoidable death'^of 

 the somatic body. No such difference exists if we draw the correct 

 biological parallellism. If we compare the life cycle of the single-celled 

 organism in a given medium, with the life cycle of the cells of the body of a 

 higher organism, we note a very close analogy. If we inoculate a given 



