PLEA FOR INVESTIGATION OF INDIAN CULICIDIZ. 593 
would, doubtless, continue to thrive in its new host. But in the ordi- 
nary plan of nature the eggs discharged from the bowel of the eating 
animal are discharged in situations when they are likely to be 
swallowed by the eaten animal, and in the latter produce the asexually 
multiplying bladder worm. This, when swallowed with its eaten host, 
developes in the eating animal once more into the sexually multiplying 
tape-worm. 
Now, although we are acquainted with a large number of parasitic life- 
histories of this character, we know of no instance in which a parasite 
with such a history is capable of maintaining the continuity of the 
species in any other manner, and it will be, indeed, astonishing if the 
malarial parasite should prove an exception to what has been hitherto 
found to be an unvarying law of parasitism. 
_ In fact, no one who has any special knowledge of the subject will 
believe that. there can under the circumstances be any other route of 
infection. Hither the idea that the mosquito is the alternative host of 
the malarial parasite is a huge mistake, or it is, under natural cireum- 
stances, the one and only method of infection. There is no tenable 
middle position. 
Most of the apparent exceptions depend on the fact that, like most 
other two-host life-history parasites, the host carrying the sexual phase 
of the malarial parasite may do so for years without any perceptible 
inconvenience. A bladder worm may have to lie imbedded in the tissues 
of an ox for years before the animal is turned into beef and devoured 
by a man. 
Then its opportunity has come and it developes into a tape-worm, 
each sexually multiplied strikle of which is a complete hermaphrodite 
sexually mature animal. | 
So with the malarial parasite. An infected person may have no 
visible symptoms, but lurking in his tissues are the parasites ready to 
start again on their course of asexual multiplication should any acci- 
dent bring the resisting power of the hust sufficiently low. 
Hence persons who have had no recent opportunity of being bitten 
by mosquitoes often do develop a typical ague, but the fact remains 
that they must have been bitten at some time, and as a matter of fact, 
the interval is a concern of but little moment to the parasite. The 
patient, in fact, though apparently well, has latent malaria ; in other 
