SEX IN PRorozoA 203 



6V.V Dctcnniihitioii ii/ni Sex Di^Jcrcnt'hnioii 



Tclosporid'ia. 1 here is a considerable body of literature which 

 tends to show that sex determination in the I elosporidia takes place 

 soon after zygote formation, possibly during the first zygotic nuclear 

 division. Joyet-Lavergne's extensive publications show cytoplasmic 

 differences between male and female trophozoites and gamonts among 

 the I'ugregarinida, and especially among the Cephalina. It will be 

 recalled that in this group each zygote commonly gives rise to eight 

 sporozoites, each of which may grow into a gamont without further 

 division. 



Using neutral red, Aliihl (1921) showed that, for Gregarina 

 cuneatu and G. polyiitorpha from the larvae of Tenebrio molitor, the 

 two members of a pair in syzygy stained differently, although there 

 was much variation when pairs were compared to each other. Joyet- 

 Lavergne (1926) obtained similar results with the same species and 

 \\ith Stein'mx oralis. Other vital dyes, which color the cytoplasm 

 directly, such as methyl blue, cresyl blue, Nile blue, and dahlia violet 

 were used. W \x\\ these the anterior member of the pair, the primite 

 (female), stained more intensely than the posterior member, the 

 satellite (male). Tests for pH showed little or no differences between 

 the sexes, a point confirmed by Gohre (1943). Tests for golgi appara- 

 tus and for fats also showed differences in the cytoplasm of the two 

 sexes. Sex differences in the gamonts either before or after encystment 

 were show'n by these various techniques when the gamonts themselves 

 were morphologically indistinguishable and when similar gametes 

 (isogametes) were produced by the gamonts. As Gohre (1943) 

 remarked, sex differences in gregarines become apparent very early, 

 and are probably genotypic in origin. Literature in this field up to 

 1930 is reviewed by Joyet-Lavergne (1931) in his book. 



Certain conditions in the Coccidia are suggestive. In Adelina 

 deroiiis Hauschka (1943) found evidence of differential behavior 

 between the four nuclei derived from the zygote nucleus (Fig. U, 

 4), two nuclei proceeding to the next division faster than the other 

 two. This difference in division rate resulted in about twelve spo- 

 roblasts and tw^elve spores (6). It is possible that eight of these are 

 male and four female. In addition, Hauschka could recognize sex dif- 

 ferences in the second generation schizonts and their merozoites (14). 



