72 



NATURAL HISTORY. 



the similarly-situated " nippers " of the Horse. In the Deer, Ox, Sheep, and their allies there is not 

 a trace of these, as has been previously explained (page 4). As to the limbs, it may also be men- 

 tioned that the true 

 knee-joints which in 

 animals like the Horse 

 are almost entirely hid- 

 den within the general 

 skin-covering of the body 

 are much more con- 

 spicuous and free. 



The stomach is pecu- 

 liar; it Avants the "many- 

 plies," or third compart- 

 ment, but possesses the 

 "paunch," "honeycomb- 

 bag," and "abomasum," 

 the last-named of which 

 is of great length. In 

 t'ie walls of the paunch 

 Fig. A. STOMACH OF THE LLAMA. there are present two 



extensive collections of 



" water- cells," which serve their owners in good stead whilst traversing the desert or residing in 

 regions where fresh water is not to be procured except with difficulty. 



Fig. A is a view of the stomach from below (or, in other words, from the side farthest from 

 the backbone), in which it is seen that the clusters of water-cells (a and b) are arranged, one (a) 

 the larger, along part of the right border of the viscus, whilst the second (b) is transverse, the 

 remainder of the walls 

 being smooth. These /'I^WMiK! 

 water-cells, seen from 

 within in Fig. B, are 

 formed by the develop- 

 ment of septa, both 

 transverse and longi- 

 tudinal, in the sub- 

 stance of the paunch- 

 wall. They are deep 

 and narrow, much like 

 the cells of a honey- 

 comb, and have a 

 muscular membrane 

 covering their mouths, 

 in which there is an 

 oval orifice opposite 

 to each compartment 

 capable of being further 

 dilated or completely 

 closed, probably at the 

 will of the animal. 

 When fully distended, 

 these paunch-cells in Fig. B. WATER CELLS OF THE CAMEL'S STOMACH. 



the Arabian Camel are 



capable of storing a gallon and a half of water. The second stomach, or reticulum, is also modified 

 in the same direction, the usually extremely shallow cells being deep, at the same time that food is 



