NOTES ON THE HABITS OF THE SOFT-SHELL TURTLE 183 
adheres to this pole. The albumen is at first very gelatinous, 
but later becomes quite mobile. 
For studying incubation several artificial nests were pre- 
pared in small sandpiles placed in the angle of the floor and 
wall of an empty cement pond bed. Some eggs were collect- 
ed when the embryos had attained about three weeks develop- 
ment, and others when recently laid, care being taken to pre- 
serve the original position. Advanced eggs were placed so 
that the white pole would be on top. A week later, however, 
these eggs showed a new white pole, at an angle to, and 
lapping over the first. This new pole was tilted toward the 
‘ south. As the nests were placed against the vertical northern 
wall of the pond, it is obvious that the south was the direction 
of most light and heat. Apparently, then, this white pole 
forms with relation to direction of heat, rather than gravity. 
In about a month this white area has descended and com- 
pletely covered the egg, keeping pace with the growing allan- 
tois. Before incubation has proceeded far the air chamber 
appears on the bottom of the egg. ,Excessive moisture 
causes the eggs to rot, whereas too little usually merely re- 
tards development. As the émbryo grows the calcareous part 
of the shell becomes very much cracked and the shell mem- 
brane, yielding te pressure from within, stretches until the 
egg becomes approximately 2.39 cm. in diameter. The cara- 
pace is folded down around the young; turtle and the arms are 
extended in front of the head. The forepaws are thrust thru 
the shell first in hatching, and this opening enlarged to allow 
egress for the rest of the body. Altho the young have an egg- 
tooth below the flexible proboscis it does not seem to be used 
in escape from the eggs, and is dropped a week after hatch- 
ing. 
The young, which are very circular, have the dull olive 
carapace marked with many short black lines, and bordered 
with a margin of pale flesh color, broader to the rear. The 
feet are well webbed and immaculate below. The following 
are measurements of five newly hatched A. mutica. 
