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110 REPORT—1862. 
number of Bees in winter, hoping to ascertain the mode of development. But 
though he has met with specimens in which the female portion was so little de- 
veloped as to be even smaller than the male, still in every case the organic whole 
consisted already of these two parts. 
The youngest females contained a quantity of brownish granules, which extended 
from one end of the body to the other. As the animal increased in size, these 
granules remained stationary, and became more and more compact, so as to form 
a sort of rod. When the ovary became distinguishable, it was found that this rod, 
which in the meantime appeared to have undergone little alteration, occupied the 
lower part or uterus, with its lower end close to the vulva. In the younger females 
the eggs did not descend in the uterus as far as the “rod;” but in more mature 
specimens the eges as they made their way towards the vulva passed along the side 
of it, without breaking it up or altering its position. If therefore, as seems pro- 
bable, the “rod” is the seminal element, the impregnation of the eggs is thus sim- 
ply and thoroughly secured. 
The author also gives some account of the development of the spherules and of 
the large fat-cells. 
He expresses his regret that he has not yet been able to trace out the whole 
development, but it has not been from any want of perseverance on his part. He 
has examined in the winter months more than one hundred Humble Bees. The 
young Spherularias, however, are very difficult to find, not only on account of their 
minute size, but because in consistence, colour, and form they so closely resemble 
the nerves, muscular fibres, and other organs among which they live. He hopes, 
however, that future researches may be more successful. 
On two Aquatic Hymenoptera. By Joun Luszock, F.R.S, 
On one of the early days in August, I was looking for larvee in some water from 
a pond near my house in Kent, when I was astonished to see a small hymenopterous 
insect, swimming in the water by means of its wings. This was a phenomenon so 
surprising that at first I could hardly believe my eyes. Of the very large number of 
Hymenoptera already described, about 3500 occur in Great Britain; yet not one 
aquatic species is as yet known; while out of the whole immense list of insects, 
not one is yet recorded as using its wings under water. Hntomologists might 
fairly, therefore, require good evidence before they receive as true a statement so 
opposed to all previous experience. Not only, howeyer, did further examination 
disclose a second species, belonging to a different genus (which, however, used its 
hind legs, and not its wings, in swimming), but I was fortunate enough to succeed 
in exhibiting to the Entomological Society and also to the British Association living 
specimens of this interesting little insect. 
Moreover it is a very remarkable fact that it was again observed within a few 
days, and yet quite independently, by another entomologist, Mr. Duchess of Stepney, 
who found a single specimen. It is certainly a curious co:ncidence that, after . 
remaining so long unnoticed, it should be found by two separate observers within 
a few days of the same time. Perhaps this may be, in part at least, accounted for 
by supposing that during this season it has been more common than usual. I for- 
warded some specimens to Mr. Walker, who at first considered them to belong to 
Polynema fuscipes, but on a more careful examination satisfied himself that they 
belonged to a different and hitherto undescribed species, which I propose to name 
P. natans. 
Although it did not carry any external air-bubbles down with it, still it was able 
to remain alive under water for about twelve hows. The family to which it 
belongs pass their early stages as parasites within other animals, and the perfect 
insect probably enters the water in search of a suitable victim in or on which she 
may lay her eggs. Nevertheless the essentially aquatic habits of the species are 
proved by the fact that the male goes under water as readily as the female. 
Without the assistance of figures, it would be useless to attempt any description 
of the separate parts; but I may remark that if this insect had been extinct, 
however perfect its remains might have been, no entomologist would have 
doubted that, like its congeners, it was entirely an aérial insect. 
