706 THE AMERICAN NATURALIST.  [Vor. XXXIV. 
rotated together in the egg. On the sixth day the yolk was 
covered with a vascular network, and on the ninth it had been 
incorporated in the body. On the fourth day, when the 
embryo was turning actively, the heart was beating, and on 
either side of it there was a trace of a gill; a vein and artery 
were seen running parallel in the gill. In the course of the 
next few days the gills had first increased and become blood- 
red, then diminished, and on the seventh day only a red spot 
remained, which disappeared on the ninth. Bavay’s observa- 
tions were made in Guadeloupe, and it is possible that on this 
island there is a frog differing from Hylodes martinicensis in 
the points indicated by Bavay’s description. 
A study of two stages of the excretory system of Hylodes 
led Selenka (82) to the opinion that the embryonic and per- 
manent kidneys develop earlier than in the frog, producing a 
condition which approaches that of reptiles. 
It would be interesting to know something of the develop- 
ment of Hylella platycephala, a frog which occurs in southern 
Mexico. It is said to lay its eggs in the axils of the leaves of 
Tillandsia, where the frog ‘undergoes its metamorphosis, high 
above the ground.” 1 
Whether the entire development occurs within the egg 
membrane, and whether water continually remains on the plant 
is not stated. 
A short note on a frog, supposed to be Hylodes lineatus, 
records some evidence that its embryos undergo their entire 
development within the egg-membrane. The eggs have been 
found in Peru under grass far from water, and the embryo not 
yet hatched possessed no trace of a tail, but well-developed 
feet provided with suckers. m 
The young of Rana opisthodon hatch in the adult condition. 
Eggs were collected in crevices of rocks close to a stream on 
a peak of one of the Solomon Islands. The eggs measured 
from 6 to 10 mm. in diameter. In the younger stages the 
7 
1 Andrews ('92) reports that the eggs of a tree frog in Jamaica have been gos 
in the water at the bases of the leaves of epiphytic bromelias. They sr 
observed in early stages of development, at the end of May, in the region 
Mandeville, 
