470 ANATOMY OF VERTEBRATES. 



secondary bundles at right angles and regular intervals, so that 

 the orifice of each saceulus, of a square-shape when not con- 

 tracted, is guarded by a powerful sphincter. Some of the 

 cells are more complicated than others, being subdivided into 

 numerous loculi by folds of the lining membrane. The largest 

 of the reservoirs in the adult Dromedary, when dilated, have a 

 depth and width of about three inches. The second cavity, or 

 retieulum, has not the dense epithelial lining in either Dromedary 

 or Camel : the muscular longitudinal fasciculi forming the prin- 

 cipal ridges between the cells are less thick than the correspond- 

 ing ones of the paunch-cells : the middle fibres in each become 

 tendinous in the Llama ; but the transverse fasciculi continue 

 muscular, and spread over the circumference of the cells, con- 

 tinuously with the general muscular tunic of the cavity. In the 

 Camel the tendinous character is not obvious in the fasciculi which 

 close the primary cells of the retieulum. This cavity and the 

 paunch freely intercommunicate, and both have the same relation 

 to the oesophagus, as in true ruminants. The muscular channel 

 also exists for conveying the ruminated or remasticated food past 

 them, to a small third unlaminated cavity in the Camel, through 

 which it passes to the last or true stomach. This, however, is 

 divided by a modification of the lining membrane into two parts : 

 in the first the membrane is produced into many parallel longi- 

 tudinal folds, not covered by laminate epithelium, and gradually 

 subsiding into the ordinary ruefaB of the lining membrane of the 



^5 ** ^-^ 



rest or pyloric part of the true stomach : there may be a slight 

 constriction between the parts of the stomach above modified. 

 The pyloric protuberance exists in the Camels. 



The experiments of Clift 1 proved the direct transit of water 

 drunk by the Camel into the retieulum, where it was found 

 6 pure,' and also into the appended cells of the rumen, where it 

 was discoloured : while the concurrent testimonies of travellers 

 in the arid regions traversed by this animal establish its power of 

 there retaining water, as in a reservoir, for some days. 



In true or ordinary Ruminants the muscular fibres of the ceso- 

 phagus are disposed on two layers of spirals, taking reverse direc- 

 tions, which decussate at one or other of two opposite longitudinal 

 lines : the outer layer contains more muscular and less cellular 

 tissue than the inner one : the fibres of both are of the striated 

 kind ; and, as is usual where such are in more habitual and ener- 

 getic action, they have a redder colour than in non-ruminating 



1 xxvii. vol. i. 



