1909. | LIFE-HISTORY OF THE AGRIONID DRAGONFLY. 255 
before actually entering the leaf. The eggs are easily found in 
the thin leaves by holding these up to the light. 
East Norfolk is rich in “dragonflies * , not only in species but in 
individuals. A great number of females of Agrion pulchellum 
Lind., /schnura elegans (Lind.), Hrythromma naias (Hansen), 
Lestes sponsa (Hansen), and Hnallagma cyathigerum (Charp.) 
were ovipositing at Sutton in the end of July. Eggs were 
therefore not difficult to find; but it was a somewhat laborious 
task to collect a large number, and, apart from this, it was 
impossible to know to which species any egg belonged or how 
long it had been laid. I therefore constructed a “large cage, 
15" x 12" x 12", consisting of a wire frame covered with muslin, 
and this was placed over a large photographie developing-dish 
half filled with water. On the water I floated a few clean young 
leaves of the frog-bit (ydrocharis morsus-rane L.) cut off from 
the plant, having first examined them carefully to make sure they 
contained no dragonfly egos. I then captured six pairs of Agrion 
pulchellum Lind. and put them in the cage. It is extraordinary 
how dependent upon the direct sunlight is the vitality of these 
insects. On dull days, or when the cage was in the shade, the 
prisoners were in what appeared to bea torpid condition, clinging 
to the muslin sides of the cage and not moving for hours at a time ; 
but on a bright day, or as soon as the cage was put into the sun- 
light, the scene became one of extraordinary activity: the males 
fighting one another for the females, and the combatants con- 
stantly falling into the water, from which, however, they always 
succeeded in escaping. 
The peculiarity of the male reproductive organs—the vasa 
deferentia opening on the sternite of the 9th abdominal segment, 
while the organ of intromission is situated on that of the 2nd 
seement,—and the consequent peculiar method of transference of 
the spermatozoa to the female are apparently unique in the 
Odonata. I have never seen the actual transfer of the sperm to 
the sperm-sacs of the male, although in some individuals which 
have emerged in captivity I have noticed the tendency to curl the © 
abdomen asif making attempts to bring the 9th and 2nd abdominal 
sternites into contact. Whether the sperm is transferred to the 
sacs once and for all, or whether the supply in the sacs is 
replenished from time to time, has apparently not been observed ; 
but the female, at intervals in the process of oviposition, obtains 
further supplies of sperm from the male. 
The male is furnished with claspers at the apex of the abdomen, 
by which he grips the notum of the prothorax of the female; and 
the pair fly about attached in this manner. The adaptation of 
these parts to one another is so close that only the claspers of the 
male of its own species can hold the prothorax of a female. Thus 
one very definite means of separating the females of A. pulchellum 
* See ‘ Victoria County History: Norfolk, vol. i. (1901). Also, for Agrionide, 
«A Bionomical Investigation cf the Norfolk Broads,’ Trans. Nortolk & Norwich Nat. 
Soe. vol. vii. (1904). 
