84 
A Monograph of Culicidae. 
but the extensive collections from India have none of these 
represented. They may have come via Central Asia, through 
Turkestan, Persia, and so to Europe, existing over all that 
region, from which we have had no specimens whatever, and I 
believe this will prove to be the case. The strange occurrence 
of the Arctic C. nigripes in the same locality can then also be 
explained by its uniform distribution through Central Asia and 
Siberia to the Arctic Ocean, and not by any artificial agencies, 
such as have largely accounted for the cosmopolitan character 
of certain well-known species in the maritime provinces over 
the world. 
Nuttall and others in their papers, “ Studies in Relation to 
Malaria,” i. p. 9, refer to the dissemination along the course of 
rivers, down which the eggs, larvae, and pupae may be carried. 
These authors state that, “ If present at the head waters of a 
stream the insects certainly are carried even down to the estuary, 
coming to maturity all along the course of the river wherever 
there is a backwater, a recess in the bank, or wherever the river 
water overflows into neighbouring ditches.” This could only 
take place in a slow flowing stream. 
MOSQUITOES AS DISEASE CARRIERS. 
The subject of the diseases with which mosquitoes are 
connected have been treated fully in such writings as Ross’s, 
Grassi’s, Nut tail’s, Manson’s and others, and need scarcely be 
referred to here. But as some notes of interest have been 
received regarding mosquitoes in connection with various diseases 
brief references are made to the subject. The chief diseases 
w T ith which mosquitoes are connected are malaria, yellow fever 
and filariasis, and it is possible that other diseases may be 
transmitted from one individual to another by their agency. 
Malaria. —With regard to malaria, the theory of Dr. Manson, 
in which the chief part is played by mosquitoes, has now been 
conclusively proved by Major Ronald Ross and Professor Grassi, 
and other observers who have added their quota to this all- 
important subject. 
The researches of both Ross and Grassi show that it is the 
genus Anopheles which is the agent not only of transferring the 
malaria from one human being to another, but in which the 
