67 
moves rapidly and dives to the bottom of the water. Recovering from 
its fright, it rises obliquely to the surface. 
‘“‘Just as with the larve of Culex, the larve of Anopheles live upon 
organic microscopic particles which float upon the water, and which are 
brought into the mouth by the movements of the rotatory organs. | 
These organs are much more developed than with the larvee of Culex, 
and while they serve, like the former, as a brush or sieve to strain their 
food the larvee of foros like tires of Simulium, holding the head 
stretched forward, use them to agitate the water. The larve of 
Anopheles present this peculiarity, that in producing these currents, 
which they do the greater part of the day, they lie upon the belly 
with the under part of the head turned upward. This rotation of the 
head is executed with the greatest rapidity; and scarcely, for example, 
have the larve come to the surface to float, when, by a rotation of the 
head upon its longitudinal axis, it is turned bottom side upward and 
commences to agitate the surface of the water. This agitation is 
undoubtedly for the purpose of drawing floating objects surely and 
completely into the orifice of the mouth. This, however, is not neces- 
sary, for often one sees the larva with its head working in normal 
position, mouth organs below, but in general they do not remain in 
this position for a long time, and it is only after having turned the 
head upward that they seem to work con amore. 
**As a rule the larvee seek their nourishment while they are floating 
at the surface, but at other times they descend two or three inches 
under the water. They can rest several minutes in this position with 
the head below, after which they come to the surface again.” 
This account shows that Meinert knew the larvee very well, and one 
can only regret that he did not describe the eggs and the pupe. 
THE MALARIAL EXPEDITION OF THE LIVERPOOL SCHOOL OF TROPICAL 
MEDICINE. 
This interesting and most valuable report was known to the writer 
only by brief newspaper notes until the present bulletin had reached 
page proof—too late to insert in proper place several important obser- 
vations made by Ross, Annett, Austen, and Fielding-Ould. To-day 
(August 13) it has reached him in Volume II of the Thompson Yates 
Laboratory Reports (University Press of Liverpool, 1900), and he is 
glad of the Sebo e uit to add the following paragraphs quoted from 
its pages: 
8. METHODS FOR ASCERTAINING DEFINITIVE HOSTS. 
The long researches of one of us in India, followed by those of Koch, Daniels, and 
the Italian investigators, have given us a very exact knowledge of the life history of 
the Heemamcebide in gnats, and have shown us how to detect them in the insects 
with ease and certainty. It has been noted that in inhospitable species of gnats the 
ingested parasites perish within the stomach cavity, whereas in hospitable species 
the zygotes escape from that cavity and develop in the tissues, ultimately giving rise 
to blasts which are found in the juices and salivary glands of the insect. * * * 
