308 Sporozoa 



of the developing salivary glands and give rise to sporozoites (Fig. 6. 24, 

 X, Y). A variety of forms (Fig. 6. 24, A-J), similar to those for Theileria, 

 finally appear in the red corpuscles of cattle after sporozoites are inocu- 

 lated by a tick. These erythrocytic stages are infective for ticks. 



The life-cycles of the two genera — Babesia Starcovici and Theileria 

 Bettencourt, Franca and Borges — seem to differ primarily in the verte- 

 brate phase. Multiplication in lymphocytes, as established for Theileria 



Fig. 6. 24. Babesia bigemina (after Dennis). A-J. Stages in red corpuscles 

 of cattle; reproduction by fission is suggested by stages F-J; x4795. KM. 

 Parasites from the gut of ticks. N-P. Development of an "isogamete." Q, 

 R. Supposed stages in isogamy. S. Ookinete from gut of a tick. T. Ookinete 

 in ovum of tick; yolk globules outlined; portion of a section. U. Oocyst. V. 

 Small oocyst with five nuclei; K-V, x2818. W. Developing sporoblasts, x3270. 

 X. Sporokinetes, smear preparation from tick; x3270. Y. Group of sporozoites 

 from embryonic salivary gland of tick; xl940. 



