230 



present day in those Jiies wliicli are blnod-siu-kers but have no 

 l)itin<;' nioutli-parts. These depend on true biting' flies for the 

 making' of tlie vround. In the genus P ] ill (lem atomy ia there are 

 three species which show separate steps in the modification of the 

 y¥i/,s^c«-like proboscis to a biting apparatus. The changes all 

 depend on the increase in size and functional importance of the 

 prestomial teeth. Between the genus Fhilaemafomyia and the 

 StomoxydixVae there is a wide gap, the proboscis in the latter 

 being a piercing one in the true sense of the word. In the flies, 

 in the order given above, there is an increase in the relative length 

 of the haustellum, and a diminution in that of the rostrum, 

 together with some diminution in tlie amount of movement 

 between the latter and the head capsule. Glossiita represents an 

 extreme case ; the alterations in the structure and the diminution 

 in the amount of movement are the same in kind as in Stoiaoxys, 

 but greater in deg'ree. 



LuTz (A.). The Insect Host of Forest Malaria; 



KisAii (h\). Contentions regarding Forest Malaria, — rroc. Entovt. 

 Sac, Wash I II >jf on, xv, no. 3, Sept. 1913, pp. 108-118. 



In a paper read before the Washington Entomological Society, 

 Dr. Lutz upholds his theory that outbreaks of malaria amongst 

 men working in uninhabited forests in Brazil, far from 

 towns or dwellings, are caused by the bites of Anopheles lutzii 

 {= A. holiviensis) . In the present paper he does not state from 

 what source the mosquito itself becomes infected, but he points 

 out that it Avould be likely that mosquitos which usually feed 

 upon wild animals would take to biting human beings where 

 those animals were rare. He further ]Joints out that such 

 malaria outbreaks were common in damp marshy situations, but 

 not where it was dry; or in other words, in regions favourable 

 to the breeding of mosquitos, but not in regions unfavourable. 



13r. Knab replies to these arguments in a second paper. He 

 points out that it is unlikely that a typically forest-breeding 

 form such as A. lutzii should be capable of transmitting malaria, 

 since it is generally held on physiological grounds that the trans- 

 mission of malaria is confined to very definite species, all of 

 which frequent towns and dwellings, which A. lutzii does not. 

 He suggests that in many cases malaria has been contracted by 

 the men in towns, and has only developed after their return to 

 the forest. 



Dr. Dyar i)uts forward three alternatives to account for the 

 outl)reak of malaria under the conditions described: — (1) that 

 the true insect carrier was overlooked; (2) that the disease w^as 

 spread by .1. lutzii from a latent case among the men; and 

 (3) that there exists a form of malaria among wild animals in the 

 forest, conveyed by .4. lutzii, and that man is subject to this 

 disease when exposed to Ihe bites of mosquitos already infected 

 from wild animals. 



