THE AUSTRALIAN ‘NATURALIST: ! 175. 
produced and on the nature of the liquid, but the drop or 
minim of pharmacy is a definite volume, there being 17 
minims in a cubic centimetre, or 480 per fluid ounce. At 
this rate, and taking the specific gravity of blood ag 1.05, 
one minim would suffice to supply a meal to 32 mosquitoes, 
so that the volume of blood actually taken by an individual. 
mosquito is seen to be but small. 
Dr. 8. T. Darling (Annals Trop. Med. and Parasit. Ser- 
T.M. IV., 179, 1910) in a paper dealing with the trans- 
mission of malaria in the Panama zone, incidentally refers to- 
the quantity of blood taken by Cellia albimana, Wied., one 
of the malaria mosquitos of that region. The average weight 
of an unfed mosquito, was found to be 0.8 Mg., while that 
of those which had taken a moderate feed of blood was 1.6 
Mg., so that the average quantity of blood ingested by this 
species was just equal to its own weight, and one minim of 
blood would suffice for a meal for 76 mosquitos. In some. 
cases considerably more blood was taken by individual mos-- 
quitos, but the above figures are given by the author as re 
presentative. 
Insect-trapping Flowers. The trapping of insects by 
plants is a sufficiently common occurrence and a large variety 
of devices exist by which insects are snared. Usually, as in 
the case of the Evening Sundew (Drosera), the pitcher plants 
and many others, the plant has an end to serve, and uses the 
trapped insects as food, or in the case of some plants to in- 
sure fertilisation. There are, however, some cases in which 
the trapping of insects is purely accidental, and, far from 
being of service, is actually detrimental to the plant. An 
interesting case which came under my notice some years ago. 
illustrates this. On this occasion I captured in my garden. 
at Petersham a specimen of the common She-oak Hawk- 
moth (Maerosila casuarina, Walk.) having attached to its 
proboscis, close to the tip, an angular-shaped object, which 
examination showed to be the connate stamen pyramid of an 
introduced Apocynaceous plant, which grows in an adjacent. 
garden, and which was identified for me by Mr. J. J. Flet- 
cher as Mandevilla sauveolens, Lindl. The moth had evi- 
dently been visiting the plant for nectar, and having inserted 
its proboscis, the tip of the latter got jammed in one of the 
tapering slits on the stamen pyramid. Being unable to with- 
draw the proboscis, the moth, in its struggles for freedom, 
tore away the entire pyramid, which remained firmly fixed 
to the proboscis. The specimen as found is oxhibited. In 
order to ascertain the force exerted by the moth in pulling 
off the stamen pyramid, I tried the experiment on a number- 
of blossoms ‘of attaching a little pan by means‘of finé thread) 
