OEDEE OP EODENTIA. 439 



These animals are very numerous ; for the females bring forth 

 several times a year litters composed of ten to twelve young, 

 which are soon able to reproduce. The males are polygamous, and 

 take no part whatever in the rearing of their progenj^ 



Rats are the most destructive of all Rodents ; for although 

 their principal food is formed of seeds and roots, thej^ are, as 

 we have said, omnivorous. They make their abode in the culti- 

 vated fields, gardens, and plantations, each locality suifering by 

 their residence. Houses, barns, hay-sheds, provision-stores, 

 eewers, slaughter-houses, butchers' shops, restaurants, &c., are, 

 however, their favourite abodes. 



When a colony of Rats is established in any localitj', and no 

 longer find a sufficient supply of food, it emigrates to a new place 

 of residence. They sometimes, on such occasions, accomplish long 

 journeys. Strearas, and even the widest rivers cannot then stop 

 them. Onward appears to be their watchword, until they meet 

 with a neighbourhood suited to their requirements. One word, 

 htiwever, we have to say in their favour, on these occasions they 

 exhibit a strong spirit of fellowship, for, far from abandoning the 

 old and infirm, they come to their assistance, obviating as much 

 as possible all the difficulties that surround their situation. 



Dr. Franklin states that he has seen an old Rat, deprived of 

 sight, holding in its mouth the end of a twig, the other end of 

 which was grasped by a comrade, who thus led the unfortunate. 



So rapid is the increase of Rats, that they would be a perfect 

 scourge to humanity, if it were not for various and powerful 

 causes of destruction which limit their multiplication. Not only 

 do Owls, Buzzards, and other birds of prey, make slaughter 

 among them, but even they destroy and devour one another, 

 either for the possession of the females, or (which is the more 

 general case) in consequence of the scarcity of subsistence. 



With regard to this point, Pareut-Duchatelet relates the 

 following fact, which Magendie witnessed. The celebrated physi- 

 ologist had caused a dozen Brown Rats to be shut up in a box. 

 When he arrived home he found only three left; these had 

 devoured the nine others, and a few bones and other scattered 

 remains were all that attested of the victims' existence. 



In cities it is highly necessary that steps should be taken to 

 limit the increase of these troublesome animals ; but in spite of 



