46 CHILDHOOD OF ANIMALS 



learned pigs of country fairs, are very simple adaptations of theiri 

 natural instincts, and are no evidence for the existence of any real 

 mental capacity. 



The Ruminating Ungulates without exception have a very short 

 duration of youth in proportion to their size, and could be arranged 

 in an almost regular series in which size and duration of youth were 

 parallel. Giraffes are the largest, and their period of youth lasts 

 from six to seven years. Camels are adult in three years, llamas 

 and alpacas in rather less. Domestic cattle are adult in about two 

 years. Bison take between two and three years, and increase in 

 size for rather longer. The very large deer like elk are adult in two 

 years, but may continue to increase in size for a longer period; whilst 

 in them as in other deer, although there may not be much increase 

 in actual size, the antlers become more spreading and acquire 

 more points for many years after maturity has been attained. 

 Elands, which are the largest of the antelopes, are mature in three 

 to four years. Many of the little duikers reach their full size and 

 are adult in about twelve to eighteen months. The range of the 

 period of youth in the whole group of ruminants lies between seven 

 years and one year and follows the size of the animal rather 

 closely. It will be generally agreed that ruminants are animals of 

 low intelligence. 



We have not much information as to the duration of youth in. 

 the marsupials. The large kangaroos leave the pouch of the mother 

 permanently in from six to seven months. They grow very quickly 

 immediately afterwards, and are fully adult in from one to two 

 years. The smaller forms develop still more quickly and are 

 fully adult in from six months to a year. 



Rodents differ much in size and in intelligence. Beavers are not 

 the largest members of the group, but they are larger than most, and 

 much more intelligent than any of the others. They begin to pah* 

 when they are two years old and are fully grown at the end of 

 the third year, so that the duration of their youth may be reckoned 

 as being between two and three years. Hares may begin to breed 

 when they are a year old and are fully grown in fifteen months. 

 Rabbits have a shorter youth ; they pair when they are from five 

 to eight months old, and are fully grown in a year. Guinea-pigs 

 may begin to breed when they are three or four months old and are 

 Jull grown in from five to six months. Rats, which are born naked 

 and blind, are covered with hair on the eightlTciay, and are able to see 

 on the thirteenth day. On the twenty -first day they have reached 



