and Laboratory Methods. 



21(1: 



i 



t 



♦ 



Referring again to the growth of the parasites, it will be observed that as 

 they increase in size, the markings in the body or cytoplasm of the parasites be- 

 come more and more accentuated 

 and eventually, in the fully mature 

 parasite, present the appearance of 

 a coarse granulation or reticulum. 

 (See photomicrographs.) 



Sometimes the parasites grow to 

 be so large that they cannot accom- 

 modate themselves to the size of 

 the blood corpuscles, in which event ' 

 one end of the parasite may be con- 

 siderably bent over (PI. 1, Fig. 1), 

 and may even, according to Lang- 

 mann's observations, be bent over 

 so far as to form a loop, or bight, 

 but personally I have not seen any 

 that were disfigured to this extent. 



Langmann has also recorded the Pi ate IV — Parasite in blood of Damonia revesii 

 ,...,, , turtle, xlOUO. Red cell infected by young 



direct mvasion of the corpuscular parasite. 



nuclei by the parasites, but, though 



I have looked long and hard for such an occurrence, I have failed to observe it 



in the blood under examination. 



About three weeks ago I bought another turtle of the same species as the 



first one, and upon examination its 

 1^^ blood was found to be free from 



- * ' parasites. It was placed in the 



same aquarium with the first one, 

 and about two weeks later its blood 

 was examined again, and this time 

 it was found to be infected with 

 the same parasite as that observed 

 in No. 1 turtle, excepting that in 

 this case the majority of the para- 

 sites were found to be in the young 

 stage of development. 



I have tried to construct the 



life cycle of these parasites, but, 



up to the present time, I have not 



been successful, but hope, later 



Plate V.-Large living parasite in red blood cell of on, to have more information upon 



Shows marked this subject. 



The average size of the mature 

 parasite was found as follows : 

 Length, 9.4 /< ; diameter, 4.4 fx ; minimum length, 7.8 fi ; minimum diameter, 

 2.8 yu ; maximum diameter, 6. /v. 



Damonia revesii turtle, x 1383. 



granulation of parasite cytoplasm and shows the 



red cell nucleus down in one corner. 



