SYNGAMY AND SEX IN THE PROTOZOA 159 



when developed, perform any act of syngamy. The alleged 

 sexuality of the forms described by Schaudinn lacks the only de- 

 cisive criterion of sexual differentiation namely, sexual behaviour ; 

 and the differentiation exhibited by the two forms of trypanosomes 

 described by Schaudinn admits of an entirely different and far less 

 forced interpretation (see p. 176, infra). 



There are two further criticisms that may be made of Schaudinn's 

 theory. The first concerns the alleged universality of sexual 

 differences in living matter. It must be pointed out that, as stated 

 above, at the present time we have no evidence whatever of the 

 occurrence of true syngamy in any organisms of the bacterial 

 grade. The processes that have been interpreted by Schaudinn 

 as autogamy in certain bacteria may be much more easily regarded 

 as processes of internal regulation of the chromatin-substance. 

 Nowhere yet has the union of two distinct gametes been observed 

 in any bacterial organisms. The theory that sex is a universal 

 characteristic, and syngamy an elementary function, of living things, 

 does not rest at the present time on any basis of established fact. 



The second criticism is that the terms " male " and " female ' : 

 require definition and explanation, without which they remain 

 meaningless, connoting merely unknown, mystic properties, not 

 further analyzable, of the living substance. The characteristic 

 feature exhibited by male cells is the preponderance of kinetic 

 activity, and by female cells, of trophic functions, as Schaudinn and 

 many others have pointed out. Before Schaudinn, the same idea 

 was expressed in different language by Geddes and Thomson (114), 

 who regarded the male sex as characterized by katabolic, the 

 female sex by anabolic activities. It we suppose that these two 

 manifestations of physiological activity have each a distinct material 

 basis in the living cell, then it can easily be imagined that the 

 imperfections of cell-division may lead to the production of cells 

 in which one or the other substance predominates. This is the 

 view that Doflein (7) has developed in his very interesting critical 

 summary of the views that have been put forward upon the sexual 

 problem. He supposes, further, that these two different physio- 

 logical qualities depend upon substances which have intense mutual 

 interactions and attract each other strongly, and that a certain 

 equilibrium between them is necessary for the normal life of the 

 cell. When, therefore, one or the other substance preponderates 

 greatly in a cell, a functional derangement results ; but since cells 

 differentiated in opposite directions attract each other strongly, 

 they tend to unite, and by their union to restore equilibrium. 



The question of the sexual differentiation of the gametes is one 

 that will be discussed at greater length in the next chapter. It is 

 only necessary to point out here that a clear distinction must be 



