216 BRITISH MAMMALS 



excavates a separate burrow for herself with only one entrance 

 (like that of the mole). Ordinarily, rabbit burrows are provided 

 with an official entrance and a back door, or bolt hole. At the 

 bottom of the breeding burrow the female prepares a nest for 

 the reception of her naked young by pulling with her teeth 

 mouthfuls of fur from her chest and belly. (This habit has 

 been observed by any one who has kept tame rabbits.) In 

 captivity the domestic rabbit is shy and nervous about her 

 young, and, as every boy knows, may eat them at an early stage 

 if interfered with. It is probable that this habit exists also in 

 the wild type, though what use it can be to the species or 

 community it is difficult to understand. It almost appears to 

 be related to the instinctive eating of the placenta, or " after- 

 birth," an action performed by nearly all mammals possessing 

 teeth in whom the placenta is deciduate. The young vary in 

 number from eight to four in normal litters, and the number of 

 mammae is ten. As already mentioned, young rabbits are blind 

 and practically naked at birth. They are also very small (as 

 compared to young hares), and bear a strong superficial re- 

 semblance to the offspring of those marsupials who produce their 

 young in a most undeveloped condition. 



Rabbits are mature and able to breed at the age of six 

 months, if not earlier, and the number of litters in the year 

 may be as many as four. The obvious result of this fecundity 

 is that the increase of the rabbit when unchecked can 

 assume such extravagant proportions as to become what the 

 Germans would call a "world-force." Given favourable con- 

 ditions, and the non-intervention of man, or the lack of sufficient 

 carnivorous birds and beasts, and rabbits may ruin a continent 

 by devouring all its vegetation. It is a matter of common 

 knowledge how the introduction of the rabbit into Australia has 

 resulted in serious damage to pastures and plantations, and how, 

 if it had not been checked in a most expensive and elaborate 

 manner, it might have led to the extinction of sheep and 

 cattle, and of most of the indigenous marsupials. In a 

 natural state of affairs the increase of the rabbit in Europe 



