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reported microtubule numbers in L mexicana of 130 to 200, about twice 

 the number found in this study, indicating that the reliability of 

 microtubule counts as a means of differentiating between visceral and 

 cutaneous leishmanial forms is doubtful. 



Molyneux et _al_. (1975) examined the ultrastructure of L m. 

 amazonensis promastigotes in the midgut and pharynx of Lu . 

 longipalpis . They said that the distance between subpel 1 icular 

 microtubules is constant and therefore the microtubule count is not a 

 specific characteristic of Leishmania but is a function of the 

 diameter of the parasite. It follows that, in forms in the sand fly, 

 the microtubule number is not a reliable character for separating 

 species, but may be useful in separating developmental forms, 

 providing all counts are made at the same level within the body of the 

 parasite, e.g. at the level of the nucleus or kinetoplast. 



Molyneux et ah (1975) and Ki 1 1 ick-Kendrick (1979) reported a 

 range of microtubule numbers in nectomonads (long-slender forms) of 76 

 to 96 and in haptomonads (shorter and broader forms) of 115 to 138. 

 They did not give microtubule counts for the short-slender, highly 

 active pharyngeal and proboscis forms. Electronmicrographs of L 

 mexicana (strain WR-411) in the cardia of Lu. diabolica reveal a wide 

 variety of sizes and shapes. The range of microtubule numbers (49 to 

 151) is broader than the combined ranges of nectomonads and 

 haptomonads (76 to 138) reported by Molyneux et ^1_. (1975) and 

 Ki 1 1 ick-Kendrick (1979). The wider range reflects the three 

 morphological forms commonly seen in the cardia of Lu. diabol ica in 6- 

 day infections of L. mexicana , with the short-slender, highly active 



