SCHIZOGONY OF TRYPANOSOMA EVANSI. 55 



day. He has confirmed the observations of Salvin-Moore and 

 Breinl that small round bodies are developed in the lungs of the 

 vertebrate host at or near the maximum of the multiplication 

 of the trypanosomes in the circulating blood, and that these 

 "latent bodies" persist in the spleen and bone marrow during 

 the period when the trypanosomes are absent from the blood. 

 However, Fantham docs not agree with Salvin-Moore and Breinl 

 as to the method of development of these bodies. He was unable 

 to observe the interaction between the blepharoplast and nucleus 

 of the trypanosome described by the latter authors. In the 

 process as described by Fantham in the living trypanosome from 

 the circulating blood under the microscope, the anterior end of 

 the trypanosome disintegrates, the blepharoplast migrates near 

 the nucleus and the posterior end of the trypanosome with the 

 remnant of the flagcllum is cast off. The round body, consisting 

 of the nucleus and blepharoplast surrounded by a thin layer of 

 protoplasm, constitutes the "latent body." Fantham was also 

 able to observe the metamorphosis of the "latent bodies" into 

 trypanosomes by mixing infected spleen pulp with fresh blood 

 of an uninfected rat and observing it on a warm stage under the 

 microscope. Finally, he claims to have demonstrated the infec- 

 tiousness of this stage of the trypanosome by inoculating animals 

 with spleen pulp found by microscopic examination to be free 

 from motile trypanosomes but to contain the "latent bodies." 

 Fantham, like Salvin-Moore and Breinl, is of the opinion that 

 these bodies are a more resistant stage of the trypanosome and 

 he believes that consideration should be taken of them and of 

 the time of their development in the chemotherapeutic treat- 

 ment of trypanosomiasis. 



On the other hand, Laveran (1911), who has recently studied 

 these round bodies of Trypanosoma gambicnse in guinea pigs, 

 has come to the conclusion that they are involution forms of 

 the trypanosome, which are naturally very numerous in the 

 spleen and bone marrow at the crisis of the infection. 



Buchanan (1911) has observed some of the forms described 

 by these other authors in the internal organs, bone marrow, 

 and axillary glands of the gerbil {Gerbillus pygargus) infected 

 with Trypanosoma brucei (pecaudi) . This author describes 

 and gives illustrations of round binucleate bodies found in smears 

 from the lungs of animals killed on the sixth day of infection 

 which correspond to the "latent bodies" of Trypanosoma gam- 

 biense and Trypanosoma rhodesiense. The development of these 

 bodies, as observed by Buchanan, differs from that described 



