MORPHOLOGY IX TRICHOMONAS TERMOPSIDIS. 83 



position (Fig. I, B). These two types occurred with approxi- 

 mately equal frequency. In no case was the somatella composed 

 of more than four prospective individuals, and was always found 

 in the prophase of the second division. These somatellae were 

 much larger than might be suspected. The greatest and least 

 dimensions of ten of them (nuclei in central position) averaged 

 80.47 rnicra and 48.79 micra respectively. The extremes of the 

 greatest dimensions were 1 1 1.80 micra and 62.68 micra, and of the 

 least dimensions, 66.91 and 30.49 micra. It is quite possible that 

 these multiple fission figures are related to the giant race of 

 Trichomonas noted above that was found in some of the 

 termites examined. 



Whether multiple fission represents a definite stage in the life 

 cycle of Trichomonas termopsidis, or whether it is simply a chance 

 happening stimulated by some particular complex of circum- 

 stances, we do not know. It is significant, perhaps in favor of the 

 latter hypothesis, that multiple fission was found only in one 

 termite. 



CYSTS. 



Nothing was found on any preparations which could be identi- 

 fied with certainty as being the cysts of Trichomonas termopsidis. 

 The protozoon is probably transferred from host to host in its 

 vegetative phases. 



RELATIONSHIPS. 



This flagellate has been assigned to the genus Trichomonas on 

 purely morphological grounds that is, because of its possession 

 of a cytostome, four anterior flagella, an undulating membrane, a 

 chromatic basal rod, an axostyle, a parabasal body, and a 

 centroblepharoplast. 



Its nearest relatives appear to be Trichomonas trypanoides 

 Duboscq and Grasse, and Trichomitus termitidis Kofoid and 

 Swezy. It is difficult to state all the points of difference of T. 

 termopsidis from T. trypanoides because of the scantiness of the 

 description of the latter (Duboscq et Grassi '24.). But it is 

 certain that there is a difference in size "Les T. Trypanoides de 

 courbure normale ont une taille assez constante de 16 micra." It 

 is also found in a host, Reticulitermes lucifugus, which belongs to a 

 different family (Rhinotermi tides) from that of Termopsis (Kalo- 



