CLASS MAMMALS ! ORDER CHEIROPTERA. 



87 



Physeteridae. The Sperm Whale is found in deep water 

 in all tropical regions. 



T . , i T ' , . Fig. 139. 



It has no baleen, and is 

 distinguished by forty 

 or fifty conical teeth in 

 the lower jaw, which fit 

 into cavities in the up- 

 per ; and by a singular- 

 ly-abrupt snout with 

 blow-holes in front. An 

 immense cavity in the 

 head is filled with cells 

 containing an oil which 

 hardens into spermaceti. Ambergris is found in the intes- 

 tines in masses of thirty or forty pounds.* The food of the 

 Sperm Whale is mainly a molluscan animal called Squid. To 

 procure this, it is said to descend into the water with its 

 immense lower jaw hanging down perpendicularly. When 

 a sufficient number, attracted by the glistening color of the 

 teeth, are collected in the mouth, the treacherous jaw closes 

 and the precious morsels are swallowed. 



Skull of a Sperm Whale, PhysZter macrocephalus. 



ORDER CHEIROPTERA. 



General Characteristics. The Bats are true flying 

 mammals, the body of a beast being adapted to the life of a 

 bird. The great change is a prolongation of the fingers, 

 to sustain a semi-transparent membrane used as a wing. 

 The thumb is left free and armed with a strong claw, en- 

 abling the bat to climb walls and to suspend itself, its 

 favorite position when at rest. Its molars bristle with points 

 for crushing its insect food. Its flight is that of a bird, 

 though fluttering and lacking ease of movement. On the 

 ground it can only drag itself along by its hooked thumb- 



* This substance is very valuable, as it has the property of strengthening other 

 perfumes. It is thought to be a product of disease, as it is oftenest found in 

 sickly-looking whales. 



