226 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



Comparison of the Gastrointestinal Mucous Surfaces with that of 



the Skin. 



Animal. 



Organ. 



Partial 

 Mucous 

 Surface 

 in Square 

 Meters. 



Total 

 Mucous 

 Surface 



in 

 Square 

 Meters. 



Skin 

 Surface 



in 

 Square 

 Meters. 



Ratio 

 between 

 Mucous 

 Surface 



of 

 Stomach 



and 

 Intestine. 



Ratio 

 between 

 Skin and 

 Gastro- 

 intestinal 

 Mucous 

 Surfaces. 



Stomach, . 

 Small intestine, 

 Horse, Csecum, 



Fixed colon, 

 Floating colon, . 



0.40 

 4.39 

 1.50 

 4.29 

 1.37 



14.95 



5.50 



1 : 29.87 



1 ; 2.18' 



Ox, 



Rumen, 



Reticulum, 



Manyplies, 



Abomasum, 



Small intestine, 



Caecum, 



Colon, 



2.00 

 0.43 

 5.56 

 1.18 

 5.60 

 0.46 

 2.00 



17.23 



5.80 



1 : 7.61 



1 : 2.97 



Stomach, 

 -o- Small intestine, 

 Ho §' ' , Cascum, . . 



Colon, 



0.19 

 1.66 

 0.11 

 0.83 



2.81 





1 : 13.22 





Stomach, 



t. Small intestine, 

 -Dog, . n 



°' j Cfecum, 



Colon, 



0.12 

 0.32 

 0.005 

 0.06 



0.52 



0.88 



1 : 3.36 



1 : 0.59 



Stomach, 

 Cat, Small intestine, 

 Large intestine, 



0.02 

 0.07 

 0.02 



0.12 



0.21 



1 : 4.15 



1 : 0.58 



II. PREHENSION OF FOOD. 



1. Prehension of Solids.— By the term prehension of food is meant 

 the different methods employed by animals in seizing their food and 

 conveying it to the oral aperture of their alimentary canal. Many aquatic 

 animals, whose food consists of small particles diffused through water, 

 are supplied with an apparatus for producing currents so as to bring 

 such substances within their reach. This is especially true in the case 

 of fixed forms of life which are unable to go in search of their food. 

 Thus, the sponge and sea-mat, and various other of the lower forms of 

 life, obtain their nourishment by the production of currents in the water 

 through the vibration of cilia lining or surrounding the opening of their 

 alimentary canal. In infusoria, also, we find similar arrangements, 



