TRYPANOSOMES OF CHEIROPTERA 481 



a trypanosome of Vesperugo pipistrellus of Alsace. As they admit, they 

 have little evidence to indicate that they were not dealing with T. vesper- 

 tilionis, except that in this instance they discovered a somewhat remarkable 

 developmental process which had not been previously observed (Fig. 202). 

 By cutting sections of various organs of infected bats they noted that the 

 trypanosome reproduces within cysts which may reach a diameter of 200 

 microns. In this respect it resembles T. cruzi, and is placed by them in 

 the genus Schizotrypaymm . As will be shown below, there is no actual re- 

 production by schizogony of T. cruzi, which multiplies by binary fission 

 like all other trypanosomes, so that there is no valid ground for placing it in 

 a separate genus. For the same reason the form described by Chatton and 

 Courrier will be included in the genus Trypanosoma. The cysts referred 

 to above were found in various situations — mucosa and submucosa of the 

 stomach and intestine, the gall bladder, kidney, bladder, spleen, ovary, 

 uterus, epididymis, and peritoneum. Within the cysts there occurred flagel- 

 lates of various forms, but in any individual cyst all the flagellates were of 

 the same type. The simplest forms seen were short stumpy crithidia forms. 

 It appears as if multiplication occurs within the cysts by repeated division 

 of these forms. When the cyst is mature the short forms increase in 

 length, and finally become the typical trypanosomes, which escape into the 

 blood by rupture of the cyst. It will be noted that in this trypanosome 

 the reproducing forms are of the short crithidia type, whereas in the cysts 

 of T. cruzi, to be described below, the multiplying forms are of the leish- 

 niania type. The trypanosomes which appear in the blood of the bat do 

 not differ from T. vespertilionis, as described by other observers, so that it 

 seems highly probable that Chatton and Courrier have observed the 

 reproductive process in T. vespertilionis for the first time. Coles (1914) 

 gave a description of T. vespertilionis of the English bat. He noted that 

 in the heart blood there occurred, beside the typical trypanosomes, 

 immature forms which from his microphotographs appear to have a 

 close resemblance to the stumpy crithidia forms seen by Chatton and 

 Courrier within the cysts. Very similar forms have been seen in smears 

 of the liver and lung by Franchini (1921). 



As regards the method of transmission of the trypanosomes of bats 

 very little is known. Gonder (1910) discovered trypanosomes in the 

 stomach of mites (Liponyssus arcnatus) taken off bats. He believed that 

 the mite would be found to be thevector of T. vespertilionis. Nicolle and 

 Comte (1909), however, suspected the bug, Cimex pipistrelli, which is 

 frequently found on young bats in Tunis, and Pringault (1914) claims to 

 have transmitted the trypanosome to four out of five bats by the bite of 

 this bug. Bats were also infected by inoculating them with crushed bugs. 

 Sergent, Et. and Ed. (1921a), have noted the occurrence of flagellates of the 



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