Prof. Owen on the Ruminant Quadrupeds. 63 



trochanters on the femur, in having the fore-part of the astragalus 

 equally divided, and in having the pattern of the grinding surface of 

 the molar teeth more or less symmetrical. The horned species havejB 

 the horns in one pair, or two pairs. All have the stomach more or less^^ 

 complex, and the caecum small and simple. In the Hog the gastric 

 complexity is least displayed; but in the Peccari the stomach has three,, 

 compartments ; and in the Hippopotamus it is still more complexd^ol 

 But the most complex and peculiar form of stomach is that which 

 enables the animal to *' chew the cud," or submit the aliment to a 

 second mastication, characteristic of the large group of even-hoofed 

 Uriffulata, CR\]ed *' Ruminantia.'* "-■^'m 



These timid quadrupeds have many natural enemies ; and if they 

 had been compelled to submit each mouthful of grass to the fall 

 extent of mastication which its digestion requires, before it was 

 swallowed, ■ the grazing ruminant would have been exposed a long 

 time in the open prairie or savannah, before it had filled its stomach. 

 Its chances of escaping a carnivorous enemy would have been in a 

 like degree diminished. But by the peculiar structure of the rumi- 

 nating stomach, the grass can be swallowed as quickly as it is cropped, 

 and be stowed away in a large accessory receptacle, called the " ru- 

 men,'* or first cavity of the stomach ; and this bag being filled, the. 

 ruminant can retreat to the covert, and lie down in a safe hiding- 

 place to remasticate its food at leisure. 



The modifications of the dentition, oesophagus, and stomach, by 

 which the digestion in the Ruminantia is carried out, wei^j^ , described 

 and illustrated by diagrams. .-iji -u,iv - j ./id 



The speaker next treated of the various kinds of horns and antlers jj-i, 

 the manner of growth, shedding, renewal, and annual modificationsj, ? 

 of the deciduous horns, the peculiarities of the persistent horns, th%,' 

 mechanism of the cloven foot, and the provision for maintaining ih&r:. 

 hoofs in a healthy condition, were pointed out. , ,^q 



The following were the chief varieties of the ruminating stomac^i. 

 In the small Musk-deer {Tragulus) there are three cavities, with 8^,-^ 

 small intercommunication -canal between the second and last cavity ; , 

 the " psalterium," or third cavity, in the normal ruminating stomach, 

 being absent. This cavity is likewise absent in the Camel-tribe, which 

 have the cells of the second cavity greatly enlarged, and have also.^j 

 accessory groups of similar cells developed from the rumen, or first}| 

 cavity. These cells can contain several gallons of water. The rela^^i 

 tion of this modification, and of the hump or humps on the back, to^, 

 the peculiar geographical position of the Camel-tribe, was pointed outr^^ 



The modifications of the ruminating stomach ; the discovery of TVk^^ 

 dimental teeth in the embryo Ruminantia, which teeth (upper incisor^.^ 

 and canines) have been supposed to characterize the Pachyderms ^^p 

 the occurrence of another alleged pachydermal character, viz. the,.' 

 divided metacarpus and metatarsus, in the foetus or young of all rum^ji 

 nants, and its persistence in the existing Moschus aquaticus, and in ^.., 

 fossil species of Antelope ; the absence of cotyledons in the chorion of 

 the Camel-tribe, with the retention of some incisors as well as canines 

 in the upper jaw of that tribe ; the ascertained amount of visceral(^. 

 and osteological conformity of the supposed circumscribed prdei^i 



