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136 DISCUSSION monas forms there also. In connection with the parasites of kala-azar, Captain Patton's study of the herpetomonas forms was useful in throwing Hght on these parasites. He (Dr. Wenyon) had seen herpetomonas-Hke forms in the melophagus of the sheep, and several other insects. There one frequently found these forms hanging on to the epithelium of the gut, but the cycle did not necessarily pass directly on from round forms to flagellate and then back to round forms again as indicated by Captain Patton. Possibly, when the nutriment in the intestinal tract becomes deficient, then the herpetomonas attach themselves to the gut and become what is called a " resting " form. When fresh nutriment passes into the gut the herpetomonas detach themselves and again become free swimming flagellate forms.

Sir Patrick Manson said it was very evident that the subject was an exceedingly complicated one. It was very dangerous for anybody to assume that the life-history of the Leishman body was even approximately known. One thing that had struck him in looking at the figures given by Captain Patton was that they differed con- siderably from the figures given by Colonel Leishman (and, he rather thought, by Captain L. Rogers) represent- ing the development of the Leishman body in artificial cultures. If he recollected aright, Leishman represented the development of the dividing flagellate form in culture in this way : nucleus divided, blepharoplast divided, but the flagellum did not divide, the young flagellum being developed from the body protoplasm. Now, if this were ihe case, it was just possible that Captain Patton was dealing, not with a Leishman body, but with some other parasite. Another criticism he (Sir P. Manson) would offer and Captain Patton must bear in mind that though he