PARTHENOGENESIS OF FEMALE CRESCENT BODY. 183 



be expelled, have never been seen in instantaneously congealed blood 

 slides containing tropical gametes. A segmentation of the chromatic 

 substance which has progressed as far as it is shown in figs. 1 and 2 

 would also, in my opinion, be impossible during the few seconds occupied 

 by the process of congealing, unless we were inclined to concede that the 

 segmentation had already begun in the circulating blood, which, how- 

 ever, has not up to the present time been proved. We can only con- 

 tinuously observe and follow the expulsion of the microgametes in fresh, 

 uncongealed blood containing male gametes for fifteen to thirty minutes 

 after its withdrawal from the body. 



2. The chromatic particles, if they were destined for the microgametes 

 which are about to be expelled, would greatly surpass the latter in 

 number. In fig. 1 we have approximately 15 of these and in fig. 2 

 about 12. As far as I know, such a large number of microgametes is 

 never formed b} r one microgametocyte. 



3. The parasitic forms sketched in figs. 1 and 2 are much too large 

 for tropical microgametocytes. Moreover, the form of this intracellular 

 parasite is not in accord with such an hypothesis. It follows that we 

 have to do with a sporular form. Therefore, we have only to decide, 

 first, whether it is a case of a sexual segmentation or one of partheno- 

 genesis of a macrogamete, and, second, the species of the parasite. 



Forms of malarial parasites of other mammals and birds may be im- 

 mediately excluded from consideration, because it has been proved by 

 experiment that human blood can not ' be infected by these species. 

 Hence we are limited in our differential diagnosis to the tertian, quartan, 

 and tropical parasites. Figs. 1 and 2 present no point of similarity to 

 the product of a quartan schizogenesis ; the number of chromatic parti- 

 cles for the merozoites is much too great, the pigment is yellow-brown 

 and coarse, the protoplasm light violet-red, instead of light azure-blue 

 as it should be in the quartan parasite with Giemsa's stain. Moreover, 

 after an exhaustive examination of the blood ' preparation, no sign of 

 quartan infection in the form of rings, band-like parasites, or character- 

 istic gametes can be found ; finally, fig. 2 exhibits many and fig. 1 two 

 small Maurer's spots. 



When the red blood cells are infected by ring-fornied parasites, they 

 always exhibit Maurer's spots. Since I did not find a quartan infec- 

 tion during the examination of the blood, we may also exclude from 

 our discussion the parthenogenesis of the female gamete, which until 

 now has never been observed. 



A tertian schizogenesis and a parthenogenesis of the tertian macro- 

 gamete are just as readily excluded because of the morphologic aspect 



