278 Annals Entomological Society of America [Vol. V, 
Agrionid nymphs usually remain obscured among the vegetation, 
where they seize the prey which approaches them. However, 
the writer has frequently observed them to move a distance of 
30 or 40 mm. toward their prey. The general movements 
remind one very much of those of a cat stealing upon a bird. 
The body crouches low, almost touching the substratum. The 
animal moves forward slowly, with bent legs, until it is close to 
its victim, then the lower lip is suddenly darted forward and 
the prey is captured. They will also feed upon freshly killed 
Physa, and small pieces of fresh beef. 
Needham and Hart (1901, p. 17) make the following state- 
ment regarding the food of dragon-fly nymphs. ‘‘ The nymphs 
are all predatory in habit. Most species remain in ambush, 
aided by coverings of sand, mud, silt, and algal growths, and 
by their own protective coloring, until their prey wanders 
within reach. Anax junius and a few others choose their prey. 
All capture it with a marvellously sudden extension of the 
labium, bringing it into the grasp of the formidable lateral lobes. 
Almost all kinds of small aquatic animals appear on the bill of 
fare of the group as a whole. The Agrionide have a seeming 
preference for Entomostraca and May-fly nymphs. The vege- 
tation-inhabiting species have the most varied diet, including 
especially back-swimmers (otonecta) and water-boatmen (Cor- 
asa), small crustaceans, such as Asellus and Allorchestes, thin- 
shelled mollusks, like Physa, coleopterous and dipterous larve, 
and even the younger or weaker members of their own order. 
Anax takes even the thicker-shelled.univalves, like Amnzicola. 
The deep-water Epicordulia feeds principally on small mollusks, 
such as Amnicola and Physa, as well as on other life of the 
bottom. The Aeschnide, especially Anax, are most omnivor- 
ous creatures. The larger odonate nymphs eat very young 
fish, and in some cases appear to have caused a sweeping destruc- 
tion of large numbers of them.”’ 
RESPONSE TO INTENSE ARTIFICIAL LIGHT. 
There is a considerable amount of literature treating upon 
the photic responses of insects. The papers of Loeb (1905) are 
perhaps the most widely quoted. These have recently been 
translated and published. Little work has been done on the 
reactions of dragon-fly nymphs to hight and contact. Plateau 
(1888) experimented with dragon-flies, but his observations are 
