AGAMOMERMIS 163 



the alimentary canal, and on one occasion, tearing the abdomen in two, he 

 found that this enlargement contained two worms. These were the types of 

 Stiles's Agamomermis. In 1903, examining a large series of soUicitans, Smith 

 found a considerable number of adults infested by these worms, and from that 

 time on he made careful examinations of all material that came into his labora- 

 tory. The result was that every collection, from the Raritan River to Cape 

 May, was found to be more or less parasitized. None, however, were found on 

 the Newark or Elizabeth marshes. The records made by Mr. Viereck at Cape 

 May, and published in Smith's report on the mosquitoes of New Jersey, al- 

 though incomplete as omitting the month of August, are very interesting in 

 showing the proportion of infestation : 



In Doctor Smith's opinion, this roundworm is a very material check to the 

 multiplication of Aedes soUicitans, for in no case where a parasitized specimen 

 was examined were the ovaries developed. Several of the worms will sometimes 

 occur in a single adult mosquito, completely filling the body-cavity. As abun- 

 dant, however, as the parasites were they did not reduce the mosquitoes appre- 

 ciably even in those localities where they were most abundant. But it must be 

 remembered that any such reduction would not become apparent until a later 

 generation of the mosquitoes. The life of the adult is probably shortened to 

 some extent by the parasite, which does not, however, prevent migration, since 

 parasitized mosquitoes were taken far inland. Neither does the presence of the 

 parasites prevent the mosquitoes from feeding, for Doctor Smith killed infested 

 specimens that had actually bitten him. In fact, he sat for an hour one after- 

 noon at Anglesea, capturing such specimens as came to bite, and found that 

 nearly or quite one-half were infested. 



Doctor Smith also records the fact that in 1903 one of his assistants. Dr. H. 

 P. Johnson, found the young of an intestinal worm in an Anopheles larva. 



E. Gendre has recently found a similar larval nematode parasite, at Labe in 

 French Guinea, infesting the larvae of the yellow -fever mosquito (Aedes calo- 

 piis). The worms were always found in pairs, one large and one small, and in- 

 habited the general body-cavity of the mosquito larva, rolled up in the thorax. 

 The mosquito larvae, while they were growing, did not appear to suffer from the 

 presence of the parasites but retained their appetite and vivacity. No injurious 

 12 



