W. S. Patton 
149 
in Madras I find the rat snake, Zamenis mucosus, is well adapted for 
this purpose. It is then necessary to obtain some uninfected snakes of 
the same species, and by careful feeding experiments with the ticks to 
transmit the parasites. Having ascertained the method of infection as 
well as the approximate time the parasites take to appear in the peripheral 
blood of the snakes, it is necessary to repeat the experiment, and after a 
short interval to examine the lungs of the snakes for the process 
of multiplication of the parasites. It will then be possible to see what 
type of cyst first appears in their lungs and livers, and what form of 
parasite is at the same time discharged into the general circulation. 
This is the plan I have adopted in studying these parasites of mammals 
and reptiles, and I believe it is the only way their complete life cycles 
can be worked out. It can be readily understood that it is very tedious 
work, requiring great patience as numerous initial difficulties have to 
be overcome. 
Perhaps now Dr Sambon will understand my reason for referring to 
the presence or absence of ticks on snakes, and also why I consider it is 
impossible at present to say definitely, that certain parasites in the 
peripheral blood of snakes infected with haemogregarines represent 
schizonts, sporonts, and so on. Dr Sambon however believes that he is 
able to recognise these various stages, and mentions the well known forms 
of the malarial parasite in the peripheral blood of patients infected 
with this parasite, a truth I am well acquainted with; but have the 
haemogregarines analogous stages ? Dr Sambon assumes they have, 
not a very remarkable discovery in itself, but an assumption at present 
quite unjustifiable to say the least of it. Dr Sambon, I note, also 
states, “that the multiplication forms in the lungs of snakes do belong 
to the schizogonic cycle there can be no doubt. The adult schizonts of 
snake haemogregarines as far as we know invariably and exclusively 
break up within the lungs of their hosts.” The multiplication forms of 
snake haemogregarines do not exclusively develop in the lungs of snakes, 
but are just as common in their livers; Dr Sambon apparently is not 
aware of this fact. He need therefore hardly remind me, that these 
stages of snake haemogregarines in their vertebrate hosts are well known, 
and have been described by Lutz, Wenyon and himself 1 . Although Dr 
Sambon speaks of the schizogony of all his snake haemogregarines as 
occurring in the erythrocytes of the snakes, I can find no description of 
this cycle; he appears however to have seen the cysts of “ H. seligmcinni” 
1 To be accurate it is necessary to note, that Dr Sambon’s description has yet to be 
published. 
