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species. They noted that although cutaneous lesions on which sand 

 flies fed contained very large numbers of amastigotes, surprisingly 

 few leishmaniae were ingested, and a long search was needed to find 

 them in the sand fly host. This may account for the failure to see 

 amastigotes in dissections made within 18 hrs after the infecting feed 

 in Lu_. diabol ica . 



Strangways-Dixon and Lainson (1966) said that the first indication 

 of amastigote development in the insect host was between 12 and 24 hrs 

 when a few large, highly vacuolated, aflagellate forms were observed. 

 They also suggested that this early growth phase was followed by a 

 period of binary fission of the amastigote before development of the 

 flagellum. No clear evidence of this early amastigote development was 

 observed in L mexi_cana- infected Lu. diabol ica , although dividing 

 forms with extremely short flagella were seen. The above authors 

 observed transformation into promastigotes between 24 and 36 hrs after 

 the infecting feed in flies maintained at 25 C and 100% RH. The 

 earlier appearance of promastigotes between 18 and 24 hrs after the 

 infecting feed in Lll diabol ica may be due to a higher holding 

 temperature of 27°C, or it may reflect genetic differences between 

 strains. The early promastigotes figured by Strangways-Dixon and 

 Lainson (1966) are similar in size and appearance to those observed in 

 the present study. 



Kil 1 ick-Kendrick (1979) maintained that leishmanias have basically 

 three morphological forms in the fly, amastigotes, promastigotes, and 

 paramastigotes. The dominant form is the promastigote, of which he 

 observed two types in L. m. amazonensis. 



