TRICHOMONAD FLAGELLATES. 337 



Trichomonas muris Hartmann. 

 Plate 5, Figures 46-66. 



The process of mitosis in this form has been very fully discussed by 

 Kuczynski (1914) whose paper appeared while this investigation was 

 of progress. Our results differ from his of several important particu- 

 lars, especially in the discovery of the occurrence of multiple mitosis, 

 of the origin of the axostyles by splitting, and of the number of chro- 

 mosomes. In view of his detailed account only a brief summary of 

 our conclusions will be given. 



Our material has come from the albino mouse from the culture cages 

 of Professor J. A. Long, to whom we are indebted for the material, 

 and from Peromyscus mamculatus gambcli Baird from the Berkeley 

 Hills near the University. Of these wild mice 59 were examined but 

 only 38 were noticeably infected with this flagellate. No appreciable 

 difference between the Trichomonas from the two hosts is detectable 

 though the divergence of their lines of ancestry is possibly very great. 

 The albino mice, on the other hand, were somewhat more heavily 

 and more frequently infected, 42 out of 55 yielding Trichomonas on 

 cursory examination. Only two instances of a cycle of mitosis in the 

 infected mice were found. Four individuals of Microtus californicus 

 californiciis (Peale) examined contained no Trichomonas. 



The Trophozoite, 



This stage (PI. 5, Figs. 46-61) is smaller and more rotund than 

 the corresponding phase of T. augusta, its length being 10-15 fi and its 

 transdiameter 7-11 /x. The undulating membrane is relatively very 

 wide and its undulations are not so deeply incised nor so numerous. 

 The nucleus is a trifle smaller (5 /x) than in T. augusta (7 /x), and is 

 often richer in chromatin. There are no axostylar chromidia and but 

 a single row of 8-16 large cytoplasmic chromidial granules along the 

 inner side of the chromatic basal rod and parallel to it. These dis- 

 appear at the metaphase of mitosis and reappear along the daughter 

 chromatic basal rods after the division of the axostyle (PI. 5, Fig. 60). 

 The axostyle has no capitulum and projects but little posteriorly. It 

 sometimes shows (PI. 5, Fig. 50, 55) the posterior axostylar granules 

 or ring at the point of emergence. It is usually curved, especially 



