258 Professor Owen, on the Ruminant Animals, [May 2, 



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 ruminating stomach, the grass can be swallowed as quickly as 

 it is cropped, and be stowed away in a large accessory receptacle, 

 called the " rumen," 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, aesophagus, and stomach, by 

 which the digestion in the ruminantia is carried out, were described 

 and illustrated by diagrams. 



The speaker next treated of the various kinds of horns and 

 antlers ; the manner of growth, shedding, renewal, and annual modi- 

 fications of the deciduous horns, the peculiarities of the persistent 

 horns, the mechanism of the cloven foot ; and the provision for 

 maintaining the hoofs in a healthy condition, were pointed out. 



The following were the chief varieties of the ruminating 

 stomach. In the small musk-deer ( Tragulus), there are three cavi- 

 ties, with a small intercommunication canal between the second and 

 last cavity ; the " psalterium," or third cavity, in the normal rumi- 

 nating 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 accessory groups of similar cells developed 

 from the rumen, or first cavity. These cells can contain several 

 gallons of water. The relation of this modification, and of the 

 hump or humps on the back, to the peculiar geographical position 

 of the camel-tribe, was pointed out. 



The modifications of the ruminating stomach, the discovery of 

 rudimental teeth in the embryo Ruminantia, which teeth (upper 

 incisors and canines) have been supposed to characterize the pachy- 

 derms ; the occurrence of another alleged pachydermal character, viz. 

 the divided metacarpus and metatarsus in the foetus or young of all 

 ruminants, and its persistence in the existing Moschus aquations, 

 and in a 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 order Ruminantia, with the other artiodactyle (even- 

 toed) ungulata ; above all, the number of lost links in that inter- 

 esting chain which have now been restored from the ruins of former 

 habitable surfaces of the earth — all these and other similar facts 

 have concurred in establishing different views of the nature and 

 value of the ruminant order from those entertained by Cuvier, and 

 the majority of systematic naturalists up to 1840. Thus instead of 

 viewing the Anoplotherium as a pachyderm, the speaker, having 

 regard to the small size of its upper incisors and canines, to the 

 retention of the individuality of its two chief metacarpal and 

 metatarsal bones, and to the non-development of horns at any 



