On the Life History of Herpetomonas Muscae Domasticae

(3) The function of the flagellate stage is one of sexual reproduction. (4) The parasite, after entering the fly's intestine in its infective " spore stage," penetrates the intestinal wall in the upper part of the intestine, and reaches the loose areolar tissue under the lining membrane of the intestine, in which it divides by fission, multiplies, and grows to maturity. (5) The process of growth in the tissue usually occupies three days, at the end of which period the mature flagellate bores its way back to the lumen of the gut. (6) On emerging into the lumen of the gut a process of sexual conjugation takes place almost at once and cannot usually be observed after a lapse of 15 minutes after the migration of the parasite. (7) After one to two hours during which the macronucleus divides and gives origin to a number of minute spherical spores, a process of