534 NATURAL HISTORY OF THE HAMSTER. 



for any length of time. Sulzer has moreover found in the 

 duodenum a tape-worm, but which he could extract only in 

 fragments. It was extremely flimsy, and its joints were 

 broader than long. 



Propagation. — About the end of April the hamsters begin 

 to copulate. The male visits the female in her burrow, and 

 resides with her for a few days only. They then evince suf- 

 ficient mutual love to defend each other. Sometimes two 

 males meet in the burrow of the same female, when a furious 

 battle begins, which ends in the death or flight of the weaker. 

 The manner in which they copulate is not known, as this 

 act takes place underground, and has never been observed in 

 captivity, although much pains have been taken to make^hem 

 propagate in rooms. As soon as the act is completed the 

 female drives the male away. The duration of pregnancy is 

 not known, but it is about four weeks. Many females have 

 been taken when the males were with them. They grew big 

 and thin again, without their litter appearing ; this is explain- 

 ed by an observation of Dr. Sulzer's, who saw a female which 

 he had kept for some time, in the very act of devouring a 

 young one to which she had just given birth. He killed her, 

 and found in the uterus six others which were capable of 

 living. When taken out of the foetal membranes they were 

 blueish, but became almost as red as blood when dry. Six 

 hours after, nascent hairs were distinctly perceived. When 

 a female is caught with her litter, she will continue to suckle 

 them. The young are born blind and naked, but with the 

 full number of their teeth. Their blindness lasts eight or 

 nine days. The number of one litter is from 6 to 18, accord- 

 ing to the age and size of the female, which brings two litters 

 at least every year. As the young of the first litter get fit 

 for propagation within the same season, an old female may 

 produce up to 100 individuals of her species in one year. 

 The age to which the animal lives appears to be eight or ten 

 years. The young grow very rapidly, and begin to dig when 

 but a fortnight old. It is a curious fact, that though the 

 male and female, when alone, will make a stout defence, when 

 dug after by men, long before they are driven to the farthest 

 end of their burrows, yet the female, when with her litter, 

 will leave them in the lurch, stop the turn-again passage of 

 her burrow with earth, and dig away as fast as she can, often 

 as many as four or five feet from the place where she has left 

 her young ones, before one can get at her. Were she to dig 

 in a perpendicular, instead of a horizontal direction, she 

 might be almost sure to escape for good. 



Burrows. — The subterraneous habitations of the hamster 



