RELATION OF INSECTS TO THE PARASITIC WORMS 76 



the intermediate host of AcanthocheUonema perstans. Wellman (1907) 

 has reported that the larvae of this parasite are taken up by Omithodoros 

 moubata and according to his statements develop very slowly in this 

 tick, advanced stages not being found until more than two months after 

 infection of the tick. The suggestion made by Feldmann (1905), influ- 

 enced by Bastian (1904), that the larvae of A. perstans may pass out 

 of the body of the tick with its eggs into bananas and afterwards being 

 swallowed with this fruit by human beings is a mode of infection which 

 requires no consideration as a possibility without more supporting evi- 

 dence than has yet been advanced. 



Hodges (1902) observed Filaria larvae in the thoracic muscles of 

 the mosquitoes, Panoplites sp. and Aedes argenteus (Stegomyia calopus), 

 three days after they had been fed on perstans blood. Low (1903) was 

 able in one case to obtain development of perstans larvae to the sausage 

 stage in a mosquito {Chrysoconops fuscopermatus) . Fiillebom (1908, 

 1913) obtained a similar development in Anopheles maculipen/ms. F'iille- 

 born and Low obtained negative results with various species of mosquitoes, 

 sand fleas, lice and simuliids. 



AcanthocheUonema grassii (Noe, 1907) Railliet, Henry and 

 Langeron, 1912 



The adults of this nematode occur in the subcutaneous and intermus- 

 cular connective tissue and peritoneal cavity of the dog. The larvae 

 produced by the females are unusually large, about twice as long and 

 thick as the average filaria larva, and according to Noe (1907, 1908) 

 do not pass into the blood stream as is generally the case among the 

 filarias. Noe assumed that the larvas are restricted to the lymphatic 

 system, and accordingly concluded that the intermediate host would most 

 likely be a tick or similar slow feeding ectoparasite. In fact he found 

 nematode larvae corresponding to those of A. grassii in Rhipicephaltus 

 sanguineus, a tick of common occurrence in regions where the dogs are 

 infested with the nematode in question. Furthermore he states that all 

 of the ticks attached to dogs infested with the nematode become infested 

 with the larval worms. Additional evidence that R. sanguineus acts as 

 the intermediate host is that the larvae in the ticks undergo growth and 

 development, at least one molting period having been observed between 

 successive stages. As R. sanguineus is a tick which falls to the ground to 

 transform from the nymphal to the adult stage, the necessary opportunity 

 is aff'orded for the transmission of A. grassii from one dog to another. 

 Noe remarks that the nymph of this tick ingests large quantities of 

 lymph. The larval nematodes taken in with the ingested lymph penetrate 

 the intestinal wall into the body cavity where they undergo the develop- 



