-215- 



development and subsequent transmission of Leishmania in nature, or in 

 laboratory-reared flies (Ki 1 1 ick-Kendrick, 1979). The large, peanut- 

 shaped flagellates with large eccentric nuclei (Fig. 4-11), observed 

 in infected and uninfected Lu_. diabol ica and Lu. shannoni , do not seem 

 to inferfere with Leishmania development in the sand fly and are 

 apparently harmless monoxenous commensals. Their identity remains 

 obscure and further study is needed to determine their complete life 

 cycle. 



Ultrastructure Studies 



Gardener (1974) and Veress et al_. (1980) indicated that 

 ultrastructural studies of amastigotes have shown that cell size and 

 number of subpel licular microtubules may be useful morphological 

 parameters for differentiating between visceral and cutaneous 

 leishmanial forms. Kocan _et aj_. (1984), working with isolates of 

 visceral leishmaniasis from dogs naturally infected in Oklahoma, 

 compared subpel 1 icular microtubule counts for Oklahoma dog (OKD) 

 isolates with information published on two visceral human strains, VL 

 strain (Veress et _§_]_., 1980) and LV23 strain (Gardener et a2., 1977). 

 Mean microtubule counts for the OKD, VL, and LV23 isolates were 67, 

 91, and 81, respectively, with ranges of 51 to 82 (OKD), 58 to 116 

 (LV), and 58 to 118 (LV23). Based on these numbers, and the mean 

 maximum diameters, Kocan et aj_. (1983) concluded that the OKD strain 

 was morphologically similar to L donovani . 



In the present study, the mean microtubule number (89) compares 

 well with that of the VL isolate described above (mean = 91), but the 

 range, 81 to 97, is much narrower. Other authors (Adler, 1964) have 



