STUDIES ON AVIAN HiEMOPROTOZOA. 727 



in the case of Halteridium, there is nothing inherently im- 

 probable in supposing that it holds good for the malarial 

 parasites as well ; this was, it will be remembered, Schaudinn's 

 idea also. The first essential point, however, is to show that 

 these pai'asites possess a nucleus (trophonucleus) of the true 

 hEemoflagellate type (such as is shown by the trypanosomes 

 and Halteridium), as revealed by a stain like iron- 

 hsematoxylin. 



As regards the finer structural details of the microgametes 

 of Halteridium, I have been unable to assure myself of the 

 presence of an undulating membrane and flagellar border. I 

 have examined both faintly stained and intensely stained 

 individuals, which, for all I know to the contrary, were as fully 

 developed and mature as if they had been taken from the 

 stomach of the insect; I have studied them with the best 

 objectives and with the best possible illumination. I think the 

 photos reproduced give very accurate representations of these 

 delicate and minute organisms ; and neither my friend^ Dr. 

 Reid, who has most kindly taken these photos for me, nor I 

 myself, can make out such a structure. It may be there or it 

 may not; I must leave the point unsettled. 



Certain of the microgametes in the photos show clearly the 

 centrosomic granule at one end. The opposite end is finely 

 tapering, and comparable to a cytoplasmic tail; as Schaudinn 

 pointed out, it does not appear to be of flagellar nature. The 

 end possessing the centrosomic granule is to regarded as the 

 anterior end ; it is by this end that the microgamete pene- 

 trates the female element, as can be distinctly seen in fig. j. 



As I mentioned in a former section, I examined particularly 

 cultures inoculated with blood containing these ripe gametes, 

 with a view to finding stages in the development of the 

 ookinetes. Somewhat to my surprise, I could find no indica- 

 tions of any developmental changes in the halteridia in the 

 cultures. I saw no ookinete-like phases, and, indeed, only one 

 or two halteridia which had become liberated from the cor- 

 puscles, and these appeared to be degenerating and dying. 



