85 
1 Mosquitoes as Disease-Carriers. 
Haemamaebidae or blood parasites actually undergo part of their 
development. 
Experiments conducted by both Ross and Grassi have shown 
that Culex does not act as an intermediary. Ross experimented 
with Culex fatigans, Wied., and found that the human malarial 
protozoan would not develop in it. Grassi has experimented 
with Culex penicillaris , C. albopunctatus, C. pulcritarsis, C. vexans , 
C. Hichmdii, C. pipiens, C. nemorosus and C. annulaius, all with 
negative results, and he also states that no role can be attributed 
to C. hortensis, C. spathipalpis or C. fasciatus (elegans ), nor to 
Aedes or other blood-suckers as Simulium, Ceratopogon and 
Phlebotomus . On the other hand, he has shown that certain 
Anopheles , notably A. maculipennis ( clanger), A. bifurcatus, A. 
pseudopielus ( = A. Sinensis, sub-sp.), A. superpictus and A. nigripes, 
can distribute this disease. The common spotted-winged 
European species A. maculipennis is one of the chief Anopheles 
in spreading malaria in Italy. The Crescentic parasites of 
aestivo-autumnal fever have been found in Anopheles maculipennis , 
superpictus, bifurcatus, nigripes, pseudopictus and Itossii; the 
quartan parasites in A. maculipennis and the tertian in the 
latter as well as A. bifurcatus. Ross has shown that the 
parasites develop in A. costalis, Loew, and A. funestus, Giles, in 
Africa. Dr. Christophers has found the haematozoa in A. paludis, 
mihi. Ross also showed the parasites to occur in Anopheles in 
India, but I do not feel certain in which species. Captain James 
has shown it to occur in A. Possii, Giles, and I believe Dr. Lutz 
has in A. argyrotarsis, Desvoidy. 
In any case it is now conclusively proved that the human 
haematozoan causing malaria is transmitted from man to man, 
and possibly other animals, by the agency of certain species of the 
genus Anopheles in which the parasites undergo part of their 
development. The probability is that this does not take place 
in all Anopheles alike. 
It is certainly very important that the species in which the 
malarial parasites develop should be known, and that all experi¬ 
ments should have this detail absolutely correct. The mere fact 
that Anopheles occur in a district, and that the germs are found 
in Anopheles, is not sufficient ; the species must be accurately 
determined. 
This point is very strongly urged in a letter to me from 
Dr. Daniels ; his reason for attaching so much importance to 
this subject is that “ the sequelae of malaria seem to vary greatly 
