G8 



FIRST CLASS OF THE VERTEBRATED ANIMALS. 



continual battles, aggressions, and carnage. Otliers, again, avoid the dangers of these 

 murderous combats, by feasting on carcasses recently dead, or even already putrified. 

 The Lion kills all that he eats, but the Hyaena will extract his meal from the 

 charnel-house or tomb. There are also some Carnivorous Mammalia which confine 

 themselves to sucking the blood of other animals ; some species of Weasels and Bats 

 are examples of this, especially the Polecat {Mustela putorius) and the Vampyre Bat 

 {Vampirus spectrum). The Opossums (JDidelphis) are nourished almost wholly 

 upon the eggs of other animals. The Ant-eaters ( Myrmecophaga) , being destitute of 

 teeth, feed upon Ants and other Insects which adhere to their glutinous tongue. 



The Herbivorous animals, on the contrary, as has already been observed, have their 

 jaws less powerful, moved by more feeble muscles, armed with teeth fitted for grind- 

 ing rather than biting or tearing. Their limbs are less disposed for aggression, 

 but in return, their stomach is more capacious, its sides are more muscular and 

 -.hick, and sometimes it is muUipUed and complex, their intestines are larger and 

 longer, while their forms are more massive. Those animals which Ruminate 

 (Ruminantia), that is, whose food returns a second time to the mouth through the 

 tiesophagus, to be again chewed, after having already remained in the stomach, 

 generally have horns on their foreheads, and want the incisive teeth in the upper 

 jaw. They all have four stomachs, or rather one stomach subdivided into four cavities. 

 These divisions are disposed in the following manner. The first is the Paunch 

 (ventriculus) ; this is the largest, and occupies almost the entire left side of the 

 abdomen. The second stomach or Honey-comb (reticulum) ^ being the smallest of 

 the four cavities, is placed on the right and before the Paunch. Still farther to the 

 right, and almost behind the hver, is the third stomach or feuillet {omasum), which 

 communicates by a small opening with the fourth stomach or cailhtte (ahomasum). 

 The last is analogous to that single one found in most other Mammalia, and it com- 

 municates with the duodenum or intestine, by a kind of pyloric opening. The 

 sepai'ation between the first and second stomach is not very strongly marked; but 

 the others are divided from each other by well defined contractions which prevent 

 any confusion among them. The oBsophagus is inserted on the right side of the 

 Paunch, and a kind of prolonged gutter causes it to communicate with the second and 

 third stomachs. 



When the food has just been masticated and is swallowed for the first time, it is 

 introduced into the first stomach or paunch ; afterwards into the second ; and it is only 

 after the food has been submitted to the action of these organs, after it has been im- 

 pregnated with the juices which are secreted there, and has been softened, that it re- 

 ascends through the cesophagus into the mouth, in order to undergo a new trituration 

 more perfect than the former. When swallowed this second time, the food is placed 

 in the third stomach, without having gone near the Paunch and Honey -comb. The 

 very young Ruminantia, which are still fed alone upon the milk of their mother, 

 have not yet obtained this ruminating power ; but the fluid which they suck passes 

 at once into the last stomach, just as happens among the adult animals after they have 

 ruminated. 



Several Cetacea have stomachs nearly as complicated as the Ruminantia. The 

 Dolphin (Delphinus delphis) and the Porpoise (D. phoccena), for example, have, 

 for a stomach, four cavities placed in a row, one after the other. There exists, also, 

 between the first three cavities, a kind of short canal, forming a narrow passage, 

 by means of which the communication is established from one to the other. Yet 

 none of these animals have been observed to ruminate. 



Many Rodentia have their stomach divided into several cavities by contractions ; 

 some appear to have two stomachs, but this last arrang;ement is found more particu- 

 larly among the Marsupialia, and especially in the Kangaroo-Rat (Hypsiprymnus 

 White). Those herbivorous animals which do not ruminate, commonly have the 

 oesophagus inserted towards the centre of the stomach. The latter organ is disposed 

 in a manner to prolong the stay of the food on the same side as the spleen, being the 

 left, and the orifice of the pylorus is very narrow. We may remark here, that the 

 Rodentia usually have two incisive teeth in each jaw, isolated from all the other teeth, 

 and their hinder limbs being almost always longer than the fore, dispose them natu- 

 rally to leap. 



The digestive organs both of Man and the Quadi-umana hold a medium station 

 between the Herbivorous and Carnivorous animals. Man has all the kinds of teeth, 

 the trenchant or tearing teeth, like the Cavnivora, and the molar or grind'ino- teeth, 

 like the Herbivorous animals, without any very sensible inequalities. His lower jaw 

 moves in all directions ; horizontally, like those animals which live upon herbs, and 

 pei-pendicularly, like the Carnassiers. His stomach is single, but tolerably laro^e, and 

 the sides are of a medium thickness. The rest of his organs hold a mean between 

 those two divisions of Mammalia just mentioned. 



The Bears (Ursus) and the Badgers fATeZt-i), which appear specially organized for 

 btnng carnivorous, will, however, eat, almost indifTerently, all kinds of food, drawn 

 indiscriminately from the two kingdoms of organized beings. But generally speaking, 

 it must be considered a rare occurrence to find a carnivorous animal feeding on 

 vegetables, oi" an herbivorous animal eating animal substances. This is only re- 

 marked when thoy are urged by an extreme famine, or where they have lono- been 

 domesticated, and have thence acquired the omnivorous propensity of Man himself. 

 Thus the famished Dog eats bread, and sometimes even vegetables. Cats, when 

 deprived of all nourishment, have been known to devour, in the extremity of their 

 hunger, even the flaxy fibres of a rope. The Rats, also, although organized in every 

 respect for a vegetable diet, will sometimes eat animal substances. It has been 

 remarked, that when flesh is placed in the stomach of a Horse, it remains there with- 

 out undergoing any alteration, but he has been known to eat fish ; and Goats have 

 been seen to devour animal substances, which they manage somehow to digest. 



In respect to drinking, the Carnivorous animals, whose digestion is more rapid, 

 generally experience a less urgent necessity for water than the Herbivorous tribes. 

 It has been proved by Marcorelle, that when all the other conditions continue the 

 same, they can remain without water most easily when fed upon fat and oily aliments. 

 The Camel and Dromedary are exceptions ; for, though herbivorous, they can remain 

 without drinking for many days longer than any other animal. 



The manner in which the aiammalia drink varies much. jMan swallows liquids in 



the same manner as solids, but he drinks also by suction. The carnivorous animals lap 

 up liquids, and they could be made to die of thirst by keeping their trachsea open ex- 

 ternally, which would take away from them the power of sucking up the liquid. The 

 Bear bites the water like a fruit or any other solid aUment, and neither laps nor sucks. 

 Most of the Herbivorous animals drink by suction, and to make them perish with 

 thirst it is only sufficient to paralyze their tongue. It has been said that Man is the 

 only animal who drinks without being thirsty. 



There are some animals which are seldom observed to drink ; these are chiefly cai'- 

 nlvorous. We have already noticed that the Camel and Dromedary can remain 

 several days without drinking, and this abstinence from liquids does not appear to 

 make them suffer. There are, however, in the stomachs of these animals certain 

 separate cavities, which seem to be intended to keep the fluids in reserve. In other 

 respects, animals appear to fatten in proportion as they drink less, up to a certain 

 limit, after which a too great abstinence from water makes them fall off in bulk. The 

 Horse and the Ass, according to Aristotle, form an exception to this rule, on ac- 

 count of the enormous quantity of fleshy and often dry herbs with which these ani- 

 mals fill their stomachs almost without intermission. It is customary to suppress 

 the drink of Pigs and other domestic animals gradually when it is wished to fatten 

 them, 



Marcorelle, a member of the ancient Academic des Sciences, made several experi- 

 ments to ascertain the effect of drinks upon the bulk of the body. He passed two 

 entire months without drinking water, wine, or any other fluid ; and he lost, during 

 that interval, five pounds and a half of his entire weight; he at first weighed 120 

 pounds. After this he resumed his usual diet, eating the same things as before, but 

 adding to it wine, either pure or diluted with water. During six days of this altered 

 regimen he recovered six pounds of his substance, that is, one eleventh part more 

 than what he had lost. He observed also, that vegetables, of all food, were the 

 most liable to excite his wish for drink. We are not, however, to infer from this, 

 that drinking much is favorable to enhonpoint ; for the contrary is nearer the truth. 

 Too much drink fatigues the stomach, and weakens the digestion of the food. Tea, 

 and other hot drinks, hasten the digestion ; but it is rather to hurry it on, than to 

 accelerate it beneficially, for such drinks occasion the aliment to pass through the 

 pyloric duct before being sufficiently chymified. In respect to alcohol and other 

 exciting fluids, spicy, salt, or acid, these fluids favor the production of chyle, and, 

 in one sense, they occasion a more abundant flowing of the intestinal juices, gastric, 

 pancreatic, and biliary. But alcoholic drinks ultimately Impede nutrition by the ex- 

 citement which they cause in all the organs, in unnaturally quickening the pulsations 

 of the heart They are also injurious from interrupting the sleep, which they render 

 either short or troubled. 



Whatever may be the nature of the food, or In whatever animal it may be depo- 

 sited, the alimentary mass accumulated in its stomach usually remains there one or 

 more hours before any considerable alteration can be perceived. After that, the 

 ahments begin to soften, to change their colour, and often their smell. With the 

 exception of those grains which are entirely covered by an insohible epidermis, the 

 change begins on the surface of the alimentary substances; and it must be remarked, 

 that the properties of the chyme differ exceedingly according to the kind of food 

 from which it results. Those herbs which have been triturated and twice masticated 

 by the Ruminants give a different stomachic product than animal food, or the grains 

 of the Cerealia. It may also be observed, that the digestion of animal substances is 

 more rapid than that of a vegetable diet. Accordingly, the Carnivorous animals 

 digest their food more rapidly than the Herbivorous ; and Man, with the Plantigrada, 

 which are omnivorous, digest meat more rapidly than leguminous plants or fruits. 

 It often happens with these animals, that vegetable food will traverse the entire in- 

 testinal canal, without having lost its natural and distinctive qualities, or being in 

 any way altered, which happens very rarely with animal substances. 



The aliment, when softened and digested by the stomach, being now chyme., forms 

 a mass neai'jy homogeneous, and of a different colour in difl'erent animals, but usually 

 grayish in our species, and in several others, of a sharp odour and taste, and, from its 

 acidity, turning all vegetable blues into red. 



In the greater number of Mammalia, it is the stomach alone which performs this 

 first part of digestion — the formation of chyme, and the intestines do not proceed to 

 transform the chyme into chyle, until the moment when the stomach has completed 

 this preliminary process. But there are some animals among whom the relative 

 functions of the stomach and intestines are not confined to these definite functions. 

 The Horse, for example, which has a very narrow stomach, and yet will eat without 

 intermission for several hours, cannot retain the food in his confined stomach for a 

 sufficient length of time to be completely chymified. Accordingly, the pyloric duct 

 of the Horse remains continually open, and the food passes onwards Into the intestine 

 without interruption, although not completely chymified ; and the process is com- 

 pleted by the Intestines, without this confusion of functions being in any way preju- 

 dicial to digestion. 



The time which the food takes to chymify varies much from one animal to another. 

 The Mammalia require only a few hours to perform this function, and the same thing 

 happens with the Birds of Prey; but the Serpents and the greater part of the Rep- 

 tiles require entire days and weeks to digest a single meal. The period of time 

 ■which the same animal takes for digestion is quicker or slower, according as the state 

 of its health is more or less perfect, according as the food is more or less abundant, 

 or is in a greater or less state of minute division ; and also, according to the peculiar 

 nature of the substance to be digested. The aliment is finally submitted to the 

 action of the intestinal juices, and the surrounding organs continually maintain a de- 

 gree of heat, which Is always very near to 104^ Fahrenheit. 



The minute division of the food by mastication is a process Indispensable to a rapid 

 digestion. While the teeth and jaws are performing their function, the salivary 

 glands of the mouth continue to secrete a fluid in very considerable quantity. In the 

 Ruminantia, and generally in all animals living on a vegetable diet, these salivary 

 glands are very lai'ge, while in the carnivorcus tribes they are very small. 



The entire length of the alimentai-y canal differs materially among the Mammalia. 

 Its length, with the Rmninantia, is twenty-seven times that of the bodv, while it is 



