696 THE AMERICAN NATURALIST. [VoL. XXXIII. 
Examination of the toes of living specimens of Hyla reveals 
the fact that here also the tips — pads, as they are well known 
to be in this animal — are rather richer in capillaries than are 
other portions of the feet and limbs, but the blood sinuses are 
not present. Schuberg (91) has made a detailed study of the 
toes of the Hy/a arborea, and although he does not particularly 
discuss the blood supply to the organs, his figures show not 
only that the sinuses are absent here, but they seem to indicate 
that blood vessels and capillaries are not especially abundant. 
That the pharynx also plays an important part in respiration 
is indicated by the constant vibration of the region. From 120 
to 180, or even more, of these vibrations take place in a minute, 
and in some cases they are grouped into series of about twenty 
to twenty-five extremely rapid vibrations, with periods between 
each two series during which the vibrations almost entirely 
cease. 
The supposition that these vibrations are respiratory is 
strengthened by the fact that when the animal is immersed in 
water they cease entirely, the floor of the mouth and pharynx 
being then held permanently compressed against the upper 
wall, apparently for the purpose of excluding the water. In 
this respect Autodax differs markedly from Diemyctylus, where 
the pharyngeal floor may or may not vibrate while the animal is 
out of the water, but always has a constant, though much 
slower, up-and-down movement during aquatic periods of life, 
Gage (91), Ritter (97). 
For the little published information we have regarding the 
reproduction of Autodax we are indebted to Dr. Van Denburgh. 
On July 25, 1895, this herpetologist received from Los Gatos, 
Cal., a female specimen of A. zécanus with fifteen eggs. A 
note accompanying them stated that they were found “ under 
the ‘platform in front of a barn, in dry earth next the founda- 
tion wall, and about fifteen inches or more below the surface. 
. . . There was no water within ten or fifteen feet.” Dr. 
Van Denburgh did not hesitate to consider the eggs to belong 
to the Autodax, as he found entirely similar ones in the ovaries 
of another specimen taken from the same locality on July 30 
of the same year. The female accompanying the eggs had 
