158 THE PROTOZOA 



of the defects in the process of cell division, some cells acquire more 

 " male " properties, other more " female " ; the cells preponder- 

 atingly male show greater kinetic and motile energy, those that 

 have more female qualities show greater trophic activity. With con - 

 tinued cell-division these opposite tendencies tend to accumulate in 

 certain cells which in consequence become altogether one-sided in 

 their vital activities. Thus a want of balance in the vital functions 

 is brought about, which may reach such a pitch that the organism is 

 unable to continue to assimilate and reproduce, and must die unless 

 the balance is resorted by syngamy with an individual that has become 

 specialized in the opposite direction. By the union of two gametes 

 differentiated in this manner, equilibrium is restored and the vital 

 functions are reinvigorated. No gametes, however, whatever their 

 degree of specialisation, are to be considered as perfectly unisexual, 

 but only relatively so ; a male gamete will always contain a certain 

 amount of female substance, and a female gamete a certain amount 

 of male substance, thus accounting for the possibility of partheno- 

 genesis. Schaudinn's theory of sex is thus very similar to that 

 developed by Weininger on purely psychological grounds. 



Schaudinn, whose work on Protozoa must secure full considera- 

 tion for any statement of his observations, however inherently 

 improbable the facts or the interpretations based upon thejn may 

 seem, founded his theory chiefly on data alleged to have been 

 observed by him in the development of Trypanosoma noctuae (Schau- 

 dinn, 132). According to him, an " indifferent " ookinete might 

 give rise either to male or female forms. In the formation of males, 

 certain nuclear elements were separated out to become those of 

 the daughter-cells, while certain other nuclear elements remained 

 behind and degenerated together with a quantity of residual 

 protoplasm. In the formation of females, the same two sets of 

 nuclear structures were separated out, but those proper to the 

 male sex degenerated, while those of the female sex, which were 

 just those which degenerated in the formation of males, in this 

 case persist and become the nucleus of the female gamete. Thus 

 the indifferent ookinete was supposed to be really hermaphrodite, 

 containing male and female elements mixed together, and giving 

 rise to individuals of one or the other sex by persistence of one set 

 of characters and atrophy of the other. It must be noted here 

 that these observations of Schaudinn's are entirely unconfirmed, 

 nothing similar having as yet been found by other investigators, 

 either in trypanosomes or in any other Protozoa ; and further that, 

 even if Schaudinn's observations be accepted as exact in every detail, 

 they will not bear the interpretations which he places upon them 

 namely, that the small and large forms produced as he describes 

 are males and females, since, as he himself admits, they do not, 



