98 ANIMAL FUNCTIONS. 



is tlie natural position. From this central sack, there pro- 

 ceed ten pi okmgatives, or canals, which occupy, in pairs, 

 the centre of each ray, or division of the body, of which 

 there are five to each star-fish. These prolongations, or 

 stomachs, subdivide into numerous ramifications on each 

 side, as shown by Fig. 71, c, c, which represents one ray 

 of the asteria, laid open from the upper side. Each ray 

 has two stomachs, such as are here shown, making ten for 

 every animal. 



277. Increased Complexity in the Stomach of the high- 

 er Orders. We shall not consider it necessary to describe 

 the apparatus for digestion belonging to the different 

 grades of animals as they ascend in the scale of organ- 

 ization. It will be sufficient for our purpose to state, 

 that the operations preparatory to the introduction of 

 food into the stomach, increase in some proportion to 

 the complexity of the animal organization. Thus the 

 hydra takes its food into the stomach in precisely the 

 same state that it happens to come to the mouth, and the 

 fish, snake, frog, and many other tribes swallow their 

 aliment in an entire state. Neither have the birds any 

 organs for mastication, so that in common with them, 

 they take their food in an undivided state. But the 

 birds are furnished with an apparatus for grinding the 

 materials thus swallowed, before they are introduced 

 into the stomach, thus affording an example of com- 

 plexity in the organs of nutrition, proportionate to the 

 general scale of organic development which these ani- 

 mals exhibit. In all the warm-blooded quadrupeds, the 

 food is prepared by mastication and admixture with 

 saliva, before its introduction into the stomach. With 

 the exception of man, all animals take their food in the 

 raw, or natural state ; but with him great preparations, 

 and often very pernicious ones, are made to suit the ali- 

 ment to his pampered taste, before the act of mastication 

 commences. 



278. Man eats nearly every digestible thing. Man 

 being an all-eating animal, there hardly exists an article 

 which can be digested, in the sea, on the land, or in the air ; 

 lhat he has not, in some way or other, contrived to render 



