NECESSITY FOR EXACT DATA 185 
cially is this true of Aédes. Many species of this genus develop only in the water 
formed by melting snows and are to be found only in early spring, while others, 
are partial to tree-holes or rock-pools. The species of Psorophora breed with 
astonishing rapidity in the temporary puddles following showers, in which they 
hatch and pass the four larval stages in a scarcely greater number of days. 
To follow the complete life-history of any species and to breed it from egg to 
adult will require special experiment in each case. Many species have never been 
thus bred. In fact, our collectors have all been too much hurried, and in en- 
deavoring to breed as many isolated examples as possible in a limited time, have 
been obliged to omit the full and careful study of individual species, so much 
to be desired. Especially are we lacking in knowledge of the habits of the adults, 
their ordinary length of life, dispersal, swarming habits, etc., and these can only 
be discovered by careful, unhurried observations in the field. 
COLLECTING EGGS. 
Eggs of many mosquitoes may readily be obtained by confining captured 
females over water. Aédes will generally oviposit readily, but Culex less readily. 
Bred specimens can not often be mated in captivity, on account of the peculiar 
swarming habits, which seem essential to copulation, and which can not be 
executed in a confined space. Doctor Dyar, however, bred two generations cf 
Aédes atropalpus in a quart jar. Adults confined for oviposition require food. 
All will eat sugared water, preferably soaked into cotton, or they may be fed with 
raisins or figs. Many thrive best on mammalian blood. There are, however, few 
species that absolutely require that article of diet. Speaking broadly, mosqui- 
toes are flower-insects, living upon honey. The habit of taking mammalian 
blood, while common, is not universal, and seems to be obligatory only in the case 
of a few species. The group in general suffers in reputation from the vicious 
habits of a minority of its members. We are far, however, from wishing to imply 
that mosquitoes are negligible or harmless to man; only we can not emphasize 
too strongly the need of specific study of the different forms in order to direct 
our efforts against the dangerous or noxious species only, and not waste time 
and labor in destroying harmless or even beneficial forms. 
