138 THE ZOOLOGIST. 
instead of the more accepted signification of helmenthologists, “ intermediate 
host.” He then gave some account of the mosquito after feeding on human. 
blood. The female mosquitos, having gorged themselves, repair near 
stagnant water, and remain semi-torpid for a few days, digesting the blood 
and voiding gamboge-coloured foeces. They deposit their eggs, which float 
in sooty flakes, on the surface of the water. Soon these are hatched, and 
the larvae become the familiar “jumpers” of stagnant pools. The produce 
of Filaria, he believed, is thus taken into the human system with the 
drinking water. Dr. Manson’s method of procuring mosquitos containing 
embryo F'ilarig was to get a Chinaman, whose blood was previously ascer- 
tained to abound with Filari@, to sleep in a mosquito house. In the 
morning the gorged mosquitos were caught, and duly examined under the © 
microscope. He thus ascertained that the blood ingested by the mosquito 
from a man suffering from Filaria contains a larger proportion of Filaria 
than an equal quantity of blood obtained by pricking the finger of the same 
man. On one slide of the latter he counted under the microscope some 
twenty or thirty, in the former upwards of one hundred and twenty. He 
remarked that all embryos do not attain maturity; and dilated on the 
metamorphosis of the embryo, giving drawings of the different stages as 
observed by himself. He concluded by remarking that the Filaria, 
escaping into the water as the mosquito dies, is through the fluid-medium 
conveyed to man. Within him it pierces the tissues of the alimentary canal. 
Development and fecundation proceed apace; and finally the embryo 
Filarie, met with in the blood, are discharged in successive swarms aud in 
countless numbers—the genetic cycle being thus completed. 
Dr. Cobbold then read a paper of his own entitled “ The Life-history of 
Filaria Banerofti, as explained by the discourses of Wucherer, Lewis, 
Bancroft, Manson, Sonsino, and others.” This was 2 critical paper intended 
to elucidate the literary history of the discoveries of various observers, which 
have at length led up toa tolerably complete knowledge of the essential 
facts concerning this remarkable parasite. According to Dr. Cobbold, the 
Filaria Bancrofti is the sexually mature state of certain microscopic worms, 
obtainable either directly or indirectly from the human blood. It gives 
rise to more or less well marked diseases of warm climates, and a certain 
stage of the growth and metamorphosis of the worm takes place through the 
medium of blood-sucking insects. Dr. Cobbold concluded by offering some 
suggestions as to the best means of checking the ravages of these parasitic 
plagues; adding a notice of the various authors who have written on the 
subject.—J. Muniz. 
