January 3, 1902.] 



SCIENCE. 



15 



curing cooperation in any work that the 

 State may undertake or may suggest. 



The next species in abundance is Culsx 

 pungens. The history of this species has 

 been so well written that little remains to 

 be added to it. It is the one species of 

 Culex of which we know positively that it 

 hibernates in the adult stage. It breeds 

 everywhere in almost all sorts of places, 

 provided only there is water which is not 

 salty. I have never f ou.nd it in salt water ; 

 but in other respects it is not particular. 

 It breeds in cesspools, sewage water and 

 even in manure pits. It has no objection 

 to remaining indoors, and the larvae \\'ill 

 swarm in a neglected bucket just as readily 

 as they do in a half-filled tin can on a 

 dump. The only point of particular inter- 

 est noted in connection with this species is 

 the fact that it breeds much later in the 

 season than has been believed. Active 

 larva3 were found until late in November, 

 and even less than half -grown forms were 

 seen at that time, indicating a compara- 

 tively recent oviposition. As against this 

 species local Avork is necessary and effec- 

 tive; but it is far from necessary to treat 

 indiscriminately all sorts of bodies of 

 water. There are some places where even 

 this insect will not breed, and unless infor- 

 mation is generally distributed concerning 

 the places that actually need treatment, a 

 good deal of work will be wasted and un- 

 necessary expense incurred. 



Some very interesting information con- 

 cerning the species of Anopheles has been 

 gathered. It has been known that these 

 species hibernate as adults; the places 

 where they hibernate in the woods have 

 been discovered; the general character of 

 the breeding places has been established 

 and it has been found that the larvae may 

 be found in salt water as well as fresh. 

 This has been asserted of a European 

 species but was doubted by Dr. Howard 

 for our own. It has been also found that 



these insects continue to breed until long 

 after frost has set in. Larvae and pupee 

 were taken from ponds that had been com' 

 pletely ice covered. On at least three 

 separate occasions adults were bred from 

 larvae and pupffi after they had been con- 

 fined in or under ice for a period of several 

 hours. It is demonstrated beyond perad- 

 venture that mere cold or even an ice cover- 

 ing is not fatal to larval or pupal life of 

 Anopheles. It is further indicated from 

 the researches made that there is absolutely 

 no connection between the abundance of 

 Anopheles and the prevalence of malaria. 

 In a limited district where malaria as an 

 original disease is unknown, over two thou- 

 sand specimens of A. punctipennis were 

 taken from the cellar under a moderate- 

 sized farm-house. From the outbuildings 

 as many more were captured, in October 

 and November. Altogether about this one 

 groiip of farm buildings fully five thou- 

 sand specimens were actually taken during 

 the two months mentioned. This is, there- 

 fore, one of their commonest mosquitoes; 

 yet patients aiBicted mtli malaria have 

 come there, away off in the woods, to get 

 well; and they did so, without leaving in 

 their trail a wake of malarial cases. I do 

 not wish to be understood as doubting the 

 connection between Anopheles and malaria, 

 nor that the mosquito is necessary as an 

 intermediate host in the development of the 

 pathogenic organism. I wish only to say 

 that my investigations point to the fact that 

 there is some other factor involved and 

 that, even in the presence of an existing 

 case of malaria. Anopheles is not able to 

 transmit the disease to a healthy individual, 

 unless certain other conditions favor the 

 transmission or the development of the 

 malarial organism after it is introduced 

 into the healthy subject. 



John B. Smith. 



Rutgers College, 

 Dec. 6, 1901. 



