94 . THE UNIVERSITY SCIENCE BULLETIN. 
Seven days represented the average for 53 eggs in July. The red eye 
spots appear in such a period about the third or fourth day. A few 
eggs required 23 days to hatch in May. 
Hatching. The hatching process had not been recorded for our Ameri- 
can forms, and the writer was delighted for the opportunity to study the 
process in detail. Notes and drawings were made at the time, and are 
given herewith. While at Ithaca, N. Y., there was available in the private 
library of Mr. J. T. Lloyd, a set of the “Annals de Biologie Lacustre.” 
In volume IV, page 327 (1911), Brocher, under the title “Observations 
biologiques sur quelques insectes aquatiques,”’ gives an account of the 
oviposition, the egg and the larva of ‘“‘Lemnabates.” He figures the egg 
and the postnatal molt of an escaped nymph. In hatching, the body of 
the egg swells in one spot and gradually the shell begins to split longi- 
tudinally down one side. The embryo bulges through and in a few 
moments the red eye spots come to view and the shiny*black “eggburster” 
of the embryonic envelop (postnatal molt) shows between the eyes. (See 
pl. XIII, fig. 7.) Gradually with slight bulging movements the embryo 
works its way out until it occupies a position almost at right angles to the 
egg shell. It is still inclosed in the thin membranous envelop. The envelop 
now splits at the cephalic end (pl. XIII, fig. 10), and as it is cast the 
antennz and legs gradually appear uncovered though still folded against 
the ventral side. The head (so long and slender in the hatched bug) is 
bent at a position caudad of the eyes so that in the embryonic envelop the 
most of the head is folded on the ventral side of the embryo, the beak 
reaching nearly to the caudal end. One of the eggs observed during 
the hatching was just beneath the surface of the water and the embryo 
coming forth was partly below and partly above. Yet when the antennze 
were liberated and the head allowed to straighten and the limbs freed, 
the tiny almost transparent pale green nymph had little trouble in arriv- 
ing at an upright position on the surface film. 
Behavior of Newly Hatched. The newly hatched bug can walk upon 
the surface of the water and is soon ready to look for something to eat. 
It begins the precarious existence of the surface dwellers. A close study 
of these creatures as they go about their daily activities in field and 
laboratory, brings home to one the tragedy of life with its grim “survival 
of the fittest.” We were watching one nymph disengage itself from its 
shell. It was a slow laborious process, this particular coming into the 
world. We were relieved in a way when its postnatal molt was completed. 
Yet this feeling was short lived, for hardly had this new life righted itself 
upon the surface film and taken an inventory of its surroundings before 
there’ stalked up behind it, as we watched, another tiny nymph. This 
second fellow was a little darker (he had hatched a few hours before). 
Slowly but with definite purpose this murderous nymph slipped up behind 
the unsuspecting newly born, with beak outstretched before it. A sudden 
movement, and with a squirm of distress the little bug we had watched 
come into the world was caught upon the stylets of his brother, and its 
brief life of a few moments was over. Such is the life of the pool! Then, 
as we watched, its poor body became the banquet table of two of its 
brothers. One with its beak inserted in the joint between the femur and 
