8 4 
No. 21.—THE REPTILE HOUSE. 
This building was occupied by the collection of birds until 
the erection of the present Aviary, when the reptiles were 
moved into it. It proved, however, altogether inadequate to 
that purpose, and for some years the Society was obliged to 
neglect this important class of animals. In the summer of 
1888 alterations and enlargement of the building were under¬ 
taken, the result being the present commodious and well- 
arranged structure. 
The class Reptilia is composed of animals provided with 
lungs, a very simple digestive apparatus, and cold blood, 
a term which merely means that, unlike mammals and birds, 
so little heat is produced by the reptile itself that the temper¬ 
ature of its body depends chiefly upon that of the air or 
water which surrounds it. Many of them live in the water, 
but are compelled to rise to the surface for the purpose of 
respiration. With the exception of a few of the serpents and 
lizards, they are oviparous, and deposit their eggs on land. 
Reptiles proper are turtles, serpents, lizards, and saurians. 
The members of the class Batrachia agree in many respects 
with the above. Their spawn, or eggs, is, however, generally 
hatched under water, and they are covered with a smooth 
skin in place of the scales with which reptiles are provided. 
The young—of which the tadpole of the frog is a familiar 
example—live entirely in the water, and breathe with gills. 
In some genera, as Siren and Necturus , these gills are 
retained through life, and project from the sides of the neck, 
where they may readily be observed, the blood which fills 
them giving them a rich crimson color. In others, as the 
frogs, toads, newts, and salamanders, a complete metamor¬ 
phosis takes place, the gills of the immature animal disappear¬ 
ing altogether in the adult. In the genus Cryptobranchus the 
gills become reduced to a small orifice in the side of the neck, 
and the lungs are well developed. 
Of the amphibians, the Siren ( Siren lacertina ), the Am- 
phiuma ( Amphiuma means), and the Proteus (. Necturus 
maculatus) are usually in the collection. The two former 
are found in the soft mud of streams and ditches from Geor¬ 
gia southward. The specimens in the Garden rarely come 
