PRELIMINARY NOTES ON THE ODONATA. 81 
possess this habit. “Two combatants will fly about each other, evi- 
dently with consuming rage, when one finally appears to have secured 
often suc- 
cessfully, to tear and damage his wings.”” Everyone who has watched 
maculata has also observed this repeatedly, no doubt, and has wondered 
at the frequency of these “free fights’’ during which each male does 
his best to disable indiscriminately any or all of the rest of his kind in 
the gathering crowd. Few fatalities seem to occur, but the stronger 
may possibly tire out the weaker ones and then seize and carry off the 
females. Often a whole group of quarrelsome males may be netted at 
once, so preoccupied are they. In the case of Aeshna, where the sexes 
are very much alike, it is Walker’s opinion that nothing of the kind 
occurs and that pairing is even attempted, though prevented by the 
mutual inadaptability of the genitalia, between males and females of 
different species. He even records attempts of males to copulate with 
males and in one instance found three individuals, two males and a 
female, in tandem. In Plathemis lydia and, to a lesser extent, Libellula 
pulchella, the writer has often observed momentary conflicts between 
a position of advantage and darts at his enemy, attempting 
) 
two or more males which were trying to gain possession of a single 
female. 
Space does not allow of a summary of observations upon modes 
of copulation, but it is in general true that the prothorax (A grionidae ) 
or the back of the head (Aeshnidae and Libellulidae) is clasped by the 
terminal abdominal appendages of the male, often so vigorously as to 
leave distinct scratches or dents upon the eyes or the back of the head 
of the female (Anax, Aeshna, Gomphus, etc.). In Argia moesta 
putrida, Walker has described a condition of mutual adaptation of 
sexes so close that once firmly clasped, the female can prevent the male 
from escaping as long as she so desires. It would not be surprising to 
find this true of most damsel-flies; it is not at all uncommon to see 
the males accompanying ovipositing females of Enallagma, Lestes, etc., 
in full flight activity but apparently anchored by the female, who works 
half-submerged upon some stem. The writer has observed the males 
of Enallagma hageni drawn thus beneath the water. 
Following the capture of the female, the pair either engage in a 
wild nuptial flight (many Anisoptera) or settle down upon a rush or 
weed stem (some Anisoptera, and Zygoptera) ; while in this condition 
the female bends the abdomen forward and applies the vulva to the 
male genitalia of the second abdominal segment, the spermatic vesicle of 
which has been filled previous to pairing. When copulation is completed 
Oviposition immediately ensues, and during this later process it is not 
