STUDIES ON AVIAN H.EMOPROTOZOA. 731 



One feature about this new Leucocytozoon is of great 

 interest aud importance, tlie fact, namely, that in no instance 

 observed is the cytoplasm of the host-cell extended in the 

 form of a spindle at both sides. Even where the body of 

 the parasite is oval in shape, and more comparable in 

 form to the deeply stained portion of the body in other 

 leucocytozoa, there is no sign of any extension of the proto- 

 plasm of the leucocyte. If in the case of other species, e. g. 

 L. ziemanui, L. numid^, this great drawing out of the 

 ends of the host-cell is due merely to the parasitic influence 

 of the Leucocytozoon, why does the parasite not produce 

 the same effect here ? I certainly think it is quite as 

 probable that, in those cases where the spindle-like appear- 

 ance is shown, there is some more material cause for this 

 constant shape, and that there is really a prolongation of the 

 body of the parasite,' in the nature, perhaps, of a faintly 

 staining ectoplasmic layer, for some distance at the two 

 sides, to which is chiefly due this extension of the cytoplasm 

 of the host-cell. Upon this point, also, I shall be able to say 

 more when I have studied the preparations of L. ziemanni. 

 If this is the correct explanation, it is evident that the 

 Leucocytozoon of the chaffinch has lost its ectoplasmic 

 layer, at least so far as can be made out. This develop- 

 ment would indicate a closer adaptation to the intra- 

 cellular condition, which is also seen, perhaps, in the rounded 

 form of the parasite, the other species known being much 

 more fusiform. 



I propose the name L. f ringillinarum for this new 

 species of Leucocytozoon from the chaffinch ; the parasite 

 found by Stevenson in the greenfinch probably also belongs 

 to this same species, since, so far as I can ascertain from the 

 preparation kindly given me by Stevenson, it also has the 

 rounded form and does not cause the host-cell to become 

 spindle-shaped. 



Of the many species of Leucocytozoon now known, only 

 two or three, so far as I am aware, have been described as 

 having the rounded form, and with the host-cell lacking the 



