1.66 NATURAL THEOLOGY. 



the young litter are received at their birth ; where thoy 

 have an easy and constant access to the teats ; in which 

 they are transported by the dam from place to place ; where 

 they are at liberty to run in and out ; and where they find 

 a refuge from surprise and danger. It is their cradle, their 

 asylum, and the machine for their conveyance Can the 

 use of this structure be doubted of? Nor is it a mere doub- 

 ling of the skin ; but is a new organ, furnished with bones 

 an'd muscles of its ow^n. Two bones are placed before the 

 OS pubis, and joined to that bone as their base. These sup- 

 port and give a fixture to the muscles which serve to open 

 the bag. To these muscles there are antagonists, which 

 serve in the same manner to shut it ; and this office they 

 perform so exactly, that, in the living animal, the opening 

 can scarcely be discerned, except when the sides are forcibly 

 drawn asunder.*' Is there any action in this part of the 

 animal, any process arismgfrora that action, by which these 

 members could be formed ; any account to be given of the 

 formation, except design ? 



Ill, As a particularity, yet appertaining to more species 

 than one, and also as strictly mechanical, we may notice a 

 circumstance in the structure of the claics of certain birds. 

 The middle claw of the heron and cormorant is toothed and 

 notched like a saw. These birds are great fishers, and these 

 notches assist them in holding their sUppery prey. The use 

 is evident ; but the structure such as cannot at all be ac- 

 counted for by the effort of the animal, or the exercise of the 

 part. Some other fishing birds have these notches in their 

 bills; and for the same purpose. The gannet, or Soland 

 goose,t has the side of its bill irregularly jagged, that it may 

 hold its prey the faster. Nor can the structure in this, more 

 than in the former case, arise from the manner of employing 

 the part. The smooth surfaces, and soft flesh of fish, were 

 less likely to notch the bills of birds, than the hard bodicis 

 upon which many other species feed. 



* Goldsmith, Nat. Hist., vol. 4, p. 244. t Plate V.. Fig. ' 



