THE HJIMOPLAGELLATES. 



165 



Section IV. Mode of Infection and Habitat; Effects 

 ON Host.^ 



A. Relation of the parasites to the Invertebrate 



host. 



Schaudinn (1. c.) has minutely described the manner in 

 which the infection of Athene noctua, on the one hand. 



Fig. 4. — Diagrammatical longitudinal section through Culex 

 pipiens to show the distribution of the parasites in the body. 

 The arrows indicate the direction of their movement, the clusters 

 of stars the places of agglomeration, ul. = upper lip; l.l. = 

 lower lip ; 7ijj. = hypopharynx ; ph. = pharynx ; s.g. = salivary 

 gland ; ces. =: oesophagus ; od. = oesophageal diverticula (gas reser- 

 voirs) ; j?rov. = proventriculus ; st. = stomach ; m.t. =^ Malpighian 

 tubes; exjunction of ileum and colon; aor^. ^ aorta. (After 

 Schaudinn.) 



and Culex pipiens (females'-), on the other, is brought 

 about. For a detailed account of the complicated part played 

 by the different organs of the gnat in the act of biting, the 



* The habitat and effects upon its host of "Piroplasma" donovani 

 are discussed in Section X, it being thought preferable to consider all the 

 facts relating to this parasite at the same time. 



- Only the females of gnats and mosquitoes suck blood. 

 VOL. 50, PART 1. NEW SERIES. 12 



