THE DUCKBILL. 



Some mammals have a summer and a winter d i 



hare, al the beginning of winter, doff 

 a suit of white. The hibernation, or winter-sleep, 

 markable feature in the life <>f quadrupeds living in the 

 north temperate zone, such as tl ir, dorn and 



bats. During this period the temperature of their body 

 falls, respiration and circulation are lowered in the one 

 case, or nearly ceases in the other, and life is sustained l»v 

 their living on the fat which accumulates on the under 

 side of the neek in the so-called hibornation-glands. 



There are about 3500 species of mammals bed, of 



which 2100 are living; of these .'5lo inhabit America north 

 of Mexico. Mammals live all over the earth'- surface, but 

 mostly m the tropical regions. The _■ graphical n 

 of certain species is very great — for example, the < 

 panther, or puma ra rom British to South America 



(Chili). 



Sir. ( 1 188E8 OP M \MMAI.3. 



1. With long toothless jaws like a duels 



bill.layingeggs in a mammary pouch. Omit' ■• Duckbill. 



9 With a pouch for holding the younj im. 



Wiih a placenta; brain in most casi 

 with convolutions W 



Sub-Class 1. Ornithodelphia. 



General Characters of Monotrem.es. —The duckbill i 

 spiny ant-eater (Fig. 284, E 'lidna hystrix) are the ■ 

 representatives of the sub-class, of which then - :t a 

 single order, called Monotn ?. Bes ' - liaritiee 



the breast-bone and other parts, one <>f the most obvious ■ 

 the long, toothless jaws (there are eight horny teeth in the 

 duckbill), which are long and narrow in th 

 broad and Hat in the duckbill (Ornitl 

 dexus), where it is covered by a leathery integument; the 

 external ear is wanting. Both animals lay tru 



In the aquatic duckbill (1 _ B82) the feet are webbed, 



