410 Dr. Kidil on the Anatomy 



fill muscles, intended to move the last part ; which is tlie im- 

 mediate instrmnent employed by tlie animal in burrowing. 



It might I think be asserted, without the fear of contradic- 

 tion, that throughout the whole range of animated nature 

 there is not a stronger instance of what may be called inten- 

 tional structure, tlian is afforded by that part of the mole- 

 cricket which I am now to describe*. 



The natui'al and constant position of this member is worth 

 noticing ; the palm, as it may be called, facing outwards, and 

 the claws ranging not in a horizontal but a vertical hue, so 

 that none of them but the lowermost, and not even this neces- 

 sarily, touches the surface on which the animal is walking. 

 Accordingly the insect does not make much use of its fore 

 legs in walking ; and, if irritated, it advances towards you with 

 these legs elevated, in a menacing attitude as it were ; not un- 

 like the corresponding attitude of the insect called the Mantis. 

 The form of the hand is that of a triangle ; the base of which 

 is formed by the four claws, while the apex is situated at the 

 joint connecting this with the preceding part : by which form 

 and disposition, two important objects are gained; for the 

 joint is thus capable of a much greater extent of motion than 

 it could have possessed had the articulating surface been more 

 than a mere point; and at the same time, the greater extent 

 of the base enables it to act with more powerful and more 

 rapid effect than could have been otherwise produced. The 

 four claws which form this base constitute the proper bur- 

 rowing instrument ; and their shape and structure are beauti- 

 fully adapted to the purpose : for instead of being covered with 

 down or hair, like all the rest of the limb, they are hard, and 

 have a perfectly polished surface ; doubtless in order to pre- 

 vent as much as possible the adhesion of the earth through 

 which the animal is to make its way: they have each of them 

 sharp but strong points, which proceeding from a broad base 

 are thus rendered more effectual. In each also of the claws 

 one of the edges is shai'p, while the other is comparatively 

 blunt ; and all the cutting edges, as also the terminating points, 

 are directed downwards. Their outer surfaces are slightly 

 concave both in the longitudinal and transverse direction ; so 

 that all together they form a scoop as it were, by which the 

 earth that has been scraped off" by the points is moved out of 

 the way. They are also each of them divided longitudinally 

 on their concave side by three or four slight ridges ; so that, 

 though highly polished, their surface is not absolutely smooth : 

 and thus being concave and uneven, they ai'e more apt to re- 



* Vide Plate II. fig. 5. 



tain 



