74 8 



THE POPULAR SCIENCE MONTHLY. 



ones see the light, the mother has nourishment ready for them : part 

 of the food which she herself eats is turned into milk, and secreted by 

 special glands, so that the newly-born calf or kitten is suckled at its 

 mother's breast till it has strength to feed itself. 



Among the earliest milk-givers must have been the ancestors of 

 the curious pouched creatures of Australia, the " marsupials," which 

 have a large pouch of skin, into which the mothers put their little ones 

 when they are less than two inches long, and so imperfect that their 

 legs are mere knobs, and they can do nothing more than hang on to 

 the nipple with their round, sucking mouths, as if they had grown 

 to it. 



There the little ones hang, day and night, and their mother, from 

 time to time, pumps milk into their mouths, while they breathe by a 

 peculiar arrangement of the windpipe, which reaches up to the back 



Fig. 8. 



of their nose. Then, as they grow, the pouch stretches, and by-and- 

 by they begin to jump out and in, and feed on grass as well as their 

 mother's milk. 



Other singularly old-fashioned animals may be found in a Brazilian 

 forest. The furry little opossum, the dreamy sloth, the strange ant- 



