C. A. Hoare 
319 
2 . HAEMOGREGARINES FROM AMPHIBIA. 
Host: labelled Bufo No. 9, from Molo, July 3, 1914. 
In the blood of this host the haemogregarines are encountered in large 
numbers, both intracellularly and free in the blood plasma. The influence of 
the parasite on the erythrocyte is considerable: both the cell-body and the 
nucleus undergo alterations. We shall return to these changes below. 
The haemogregarines are represented by a whole series of forms, evidently 
representing stages of the asexual cycle of multiplication. For the sake of 
convenience, we may divide the forms met with here into the four following 
types: 
Type 1. Elongated slender form, thickened and rounded at one end and 
gradually tapering to a tail at the other (Figs. 9, 10, 11). The measurements 
of these forms are 25p, in length and 3/jl in breadth. The nucleus is elongated, 
situated nearer to the blunt end, of rather compact structure. The protoplasm 
is granulated. These forms are encountered sometimes free in the plasma 
(Fig. 9) and sometimes in the act of entering or leaving the erythrocyte 
(Figs. 10, 11). According to the data of some authors (Stebbins, 1905) the 
blunt end of the parasite should be regarded as the anterior end, as it is this 
end that is directed forwards during progression of the parasite. Therefore 
Fig. 10 represents the parasite penetrating into the corpuscle, whilst Fig. 11 
shows its emergence. Probably the temporary invasion of the blood corpuscle 
by the parasite does not remain without effect on the former. This influence 
is visible on comparing Fig. 8 with Fig. 11. Pictures similar to those described 
here from fixed preparations were observed by Stebbins (1905) in Rana 
clamata in the living state. This author states that the parasite swims in the 
blood plasma and “is able to enter and leave the blood corpuscles with the 
greatest ease and rapidity, and always mutilates the corpuscles badly in so 
doing. ' Dobell (1910) also found free forms of H. berestneffi (from Rana 
tigrina) which were actively motile. He “observed small forms enter red 
corpuscles. They did this by boring directly into the corpuscle.... Occasionally, 
the animal, after reaching the inside of the corpuscle, rested for a few minutes 
and then wriggled its way out again into the blood plasma." The same 
observer tells me that he saw similar phenomena in the case of the haemo¬ 
gregarines of the rat-snake (Zamenis mucosus). Probably the same takes place 
in our case as well. This is also demonstrated by the fact that fragments of 
erythrocytes and their free nuclei are frequently encountered amongst intact 
blood corpuscles. * 
It should be noticed here that many authors, e.g. Flu (1910), Reichenow 
(1910), Sambon (1908), Shortt (1917), assert that the extracorpuscular state 
of the parasite is due to abnormal conditions arising on account of the blood 
being exposed to the air for some time, whereas normally, and when im¬ 
mediately fixed, all the haemogregarines remain intracorpuscular. This view 
is categorically refuted by Seidelin (1911), who had “seen them free in pre- 
