174 ENTOMOLOGICAL NEWS. [April, '13 



sexual stage of a related South American species is passed in a 

 tick. Quite similar to Lankesterellft of frogs are species of the 

 genus Haemogregarina which may be readily found in turtles 

 and snakes. 



Coming closer to the malarial parasites, the bird parasites, 

 which have been so important in elucidating the life cycle of 

 the human malaria are available. I have found about 50 per 

 cent, of the crows taken around Ithaca, in the summer, in- 

 fested with Haltcridium. It is much rarer in the English spar- 

 rows. 



Protcosoma is to be found in the English sparrows at Ithaca 

 though in no such astounding percentages as Berkeley reports 

 for New York where, he states, he "found Proteosoma infec- 

 tion in 75 per cent, or more of all sparrows examined" in Sep- 

 tember. I have not found them in more than 6 per cent, of 

 those examined, and apparently Opie was no more successful 

 at Baltimore. 



Of course, occasionally opportunities for the study of human 

 malaria may arise and these will be more frequent as physi- 

 cians understand that one is prepared and willing to make such 

 examinations. 



Of the higher parasites which are insect borne the most im- 

 portant are the filariae. About three out of four of the crows 

 about Ithaca harbor at all times of the year a blood filaria 

 which is a striking object for study. Another species I have 

 found once in an English sparrow at Ithaca. Though these 

 blood filaria of the crow are five times as long as the blood 

 corpuscles, they may be present in enormous numbers. Mr. 

 Coutaunt and I have estimated that 500 occurred in a single 

 drop of blood in one specimen examined. The record is held 

 by a crow which I used in a practicum last year. The parasites 

 were so abundant that I had independent estimates made by 

 each of twelve careful students. The figures averaged nearly 

 2,000 for a single mount. No figure was lower than 2,000. 



The double-pored tapeworm, Dipylidium caninum, of dogs 

 and cats passes its intermediate stage in the flea and the louse, 

 as many as fifty cysticercoids being found in a single flea. 



