Among Polystomatidae the increase in the number of testes frona one 

 (genus Polystonnoides and others, Fig. 82) through two (Diplorchis, Fig. 

 83) to 25 and nnore ( Sphyranura , Fig. 35) is distinctly visible. The 

 greatest number of testes occurs in Microcotylidae where it can be in 

 excess of 200 annong separate representatives. However, in the odd 

 genus Mazocraeoides there is only one testis (Fig. 84). The process of 



0.1mm 



1mm 



Fig. 80, A- -Heterocotyle sp. , adult worm from the gills of Dasybatus 

 zugei M. H. from the region of Nagasaki (East China Sea), (original); 

 B--Dasybatotrema dasybatis (MacCallum), adult worm. (According to 

 Price, 1938). 



increase of the number of testes undoubtedly takes place independently in 

 the different groups. In the majority of cases this increase is realized by 

 the way of resulting division of the primary testis, mainly in a transverse 

 direction to the testis and only after that in a longitudinal direction. Thus, 

 this process takes place in all elongated forms. The increase of the 

 number of testes from the beginning by the longitudinal subdivision occurs 

 more rarely, mainly among types with considerable width. 



In certain cases the testes represent a follicular mass located 

 closer to the ventral side of the body, a nnass about which it is difficult to 

 say whether it represents a single or multiple organ (Fig. 85). Among the 



52 



