from our cistern, tightly covered; one barrel we left open to the warm
sun and air, and the other we covered with the finest mosquito netting.
The barrel left open was soon thronged with mosquitoes, constructing
their little rafts of eggs and paving their way for the swarms of young
wigglers that in the course of a week or two made their appearance in the
open barrel in immense numbers. The process by which these wigglers hatch
out into mosquitoes is an interesting one, and will bear the closest
study, as well as scientifically pay for watching the operation. At the
proper time they come to the surface of the water, undergo a palpable
modification in their structure, and beautifully burgeon forth into the
tormenting little insects that they are during the summer and autumn
months in our Northern climate. The object of the covered barrel was to
ascertain whether we could reach the conditions favorable for the
development of this little pest of the _Culex_ family, independently of
the eggs of the insect itself. This required some patience and not a
little care. We knew that an egg dropped through the interstices of the
netting would sink to the bottom of the water and fail to germinate, as
every scientist understanding the process well knows. It must be floated
on the water at first, or until it reaches the point of development into
a wiggler. The first step in the process of its life is as cunningly
devised as the second, and the second as the third, until the
full-fledged mosquito is reached.

All precautions must be taken against any mistake or error in the
experiment named. But we persevered and found nature responsive to our
demands. Wigglers after awhile made their appearance sparsely in the
covered barrel, but the mosquitoes developed from them proved innocuous of
harm, as we kept the barrel covered, and they were soon drowned in the
water, not having sufficient area of flight to answer the conditions of
their life. We might instance some remarkable discoveries in the vegetable