THE RELATIVE EGG PRODUCING CAPACITY OF SCHISTOSOMA MANSONI AND SCHISTOSOMA

Because an essential role in the pathogenesis of schistosomiasis has been ascribed to the parasite's eggs, the differential in the egg producing capacity of Schistosoma nuzn.soniand &histosoma japonicum has on several occasions been emphasized. Illustrating the comparative fecundity of two species, Brumpt (1930) states that the females of S. man8oni produce from 157 to 191 eggs per day (6 to 8 per hour) and that the females of S. bovis produce from 25 to 111 eggs per day (1 to 4 per hour). Unfortunately, Brumpt provided no data to substantiate this estimation nor did he show how he had arrived at these specific figures. Faust et at. (1934) made an effort to determine the egg output per female of S. tnansoni in monkeys by “countingall of the eggs in the first and last five per cent of a suspension of entire daily fecal samples―and subsequently deter mining the number of female worms present in the host at autopsy. These authors state that they had made no attempt to determine the number of eggs trapped in the various tissues of the host but they noted that scrapings from areas 2 cm. square of the gut revealed “tensof thousands of eggs―.From thi