REPTILES. 
THE remarkable beings which are classed together under the general title 
of REPTILES, or creeping animals, are spread over those portions of the globe 
where the climate is tolerably warm, and are found in the greatest profusion 
under the hotter latitudes. 
Some reptiles inhabit the dry and burning deserts, but the generality of 
these creatures are semi-aquatic in their habits, are fitted by their structure 
for progression on land or in water, and are able to pass a considerable time 
below the surface without requiring to breathe. This capacity is mostly the 
result of the manner in which the circulation and aération of their blood is 
effected. 
In all Mammalia and Birds, the heart is divided into a double set of com- 
partments, each having a direct communication with the other. In the Rep- 
tiles, however, this structure is considerably modified, so that the blood 1s 
never so perfectly aérated as in the higher animals. The blood is conse- 
quently much colder than in the creatures where the oxygen obtains a freer 
access to its particles. 
In consequence of this organization the whole character of the Reptiles is 
widely different from that of the higher animals. Dull sluggishness seems 
to be the general character of a Reptile, for though there are some species 
which whisk about with lightning speed, and others, especially the larger 
lizards, can be lashed into a state of terrific frenzy by love, rage, or hunger, 
their ordinary movements are inert, their gestures express no feeling, and 
their eyes, though bright, are stony, cold, and passionless. 
The young of Reptiles are produced from eggs, mostly being hatched after 
they have been laid, but in some cases the young escape from the eggs before 
they make their appearance in the world. Asa general fact, however, the eggs 
of Reptiles are placed in some convenient spot where they are hatched by 
the heat of the sun. 
TORTOISES. 
THE very curious reptiles which are known by the general name of Tor- 
TOISES are remarkable for affording the first example of a skeleton brought 
to the exterior of the body, a formation which is frequent enough in the 
lower orders, the crustaceans and insects being familiar examples thereof. 
In these reptiles the bones of the chest are developed into a curious kind of 
box, more or less perfect, which contains within itself all the muscles and 
the viscera, and in most cases can receive into its cavity the head, neck, and 
limbs ; in one genus so effectually, that when the animal has withdrawn its 
limbs and head, it is contained in a tightly-closed case without any apparent 
opening. 
In the true Tortoises the feet are club-shaped and the claws blunt, and the 
neck can be wholly withdrawn within the shell. 
Perhaps the best known species of these creatures is the COMMON LANL 
TORTOISE, so frequently exposed for sale in our markets, and so favourite an 
inhabitant of gardens. : 
This appears to be the only species that inhabits Europe, and even in that 
continent it is by no means widely spread, being confined to those countries 
which border the Mediterranean. 
EE 
