280 



Zoology. 



Vol. IV. 



est geometry, and destined to lodge and 

 nourish a posterity which is not even their 

 own. Solitary bees and wasps form also very 

 complicated nests for their eggs. From the 

 egg there springs out a worm, which has 

 never seen its mother, which does not know 

 the structure of^he prison in which it is en- 

 closed ; but, whert once it is changed into a 

 wasp or bee, it constructs a similar nest, 

 equally perfect, for its own egg. 



BONES. 



Why is fossil osteology, or the knowledge 

 of bones dug out of the eajrth, an important 

 branch of anatomy ] 



Because it not only brings to our know- 

 ledge races of animals, very different from 

 those with which we are acquainted, but sup- 

 plies many intermediate links, in the grada- 

 tion of structure, which are wanting in the 

 present creation ; and, therefore, makes it 

 probable that when the two are sufficiently 

 investigated, one regular, connected chain 

 will be formed, each class of animals imper- 

 ceptibly running into that which is next to 

 it — Sir E. Home. 



Why are bones excellent manure ] 



Because of the large proportion of lime 

 which they contain. 



Why are teeth important in identifying 

 different animals ? 



Because, by the largeness of the tooth, the 

 naturalist can judge of the real size of the 

 animal which bore it ; and by the form of the 

 tooth he can tell whether it was fitted to 

 grind grass, or to tear flesh ; and therefore, 

 whether it belonged to an herbivorous or car- 

 niverous species. Pursuing his inquiries from 

 this point, he could decide in a great degree 

 as to the structure of the stomach and vis- 

 cera : the extremities, whether armed with 

 claws or protected with hoofs ; and, farther, 

 he can judge -of the vivacity of the senses 

 which belonged to the animal, and the habits 

 which it derived from its peculiar conforma- 

 tion — knowing, beyond a doubt, tliat there 

 was an intimate agreement in all the proper- 

 ties of its existence, and that every thing in 

 its organization was regulated by an unde- 

 viating harmony. 



Why are the lives of wild animals short- 

 ened by the loss of teeth ! 



Because, as old age increases, the teeth 

 fall out, and the means of obtaining food thus 

 failing, the body sinks to rest. Man is the 

 only animal that can counteract the fatal con- 

 sequences of the loss of teeth. 



Why are the incisors or front teeth of 

 gnawing animals always sharp'! 



Because, as the teeth are covered by an 

 enamel only on their anterior or convex sur- 

 face, and the bone wears down much fiister 

 than this harder covering, the end of the 



tooth is a sharp cutting edge. No animal 

 exhibits this structure better than the rat. 



W!iy do carnivorous animals masticate 

 their food very imperfectly ! 



Because their lower jaw can only move 

 upwards and downwards, and is incapable of 

 that horizontal motion which constitutes mas- 

 tication. 



Why do other animals which live on vege- 

 tables, masticate their food thoroughly. 



Because they can move their lower jaw 

 backwards and forwards, and to either side, 

 so as to produce a grinding effect, necessary 

 to bruise grass and to pulverize grain. The 

 teeth may be compared, in the carnivorous 

 animals, to scissors ; in the other animals, to 

 the stones of a mill. — Blumenbach. 



Why do carnivorous animals prey on those 

 which derive their food from the vegetable 

 kingdom 1 



Because the food of all animals either 

 mediately or directly, is derived from the ve- 

 getable kingdom, 



Wliy are the teeth of some animals, as 

 the cow and sheep, darker in tiie centre than 

 elsewhere ] 



Because the cement which should fill up 

 the teeth, is sometimes not completely de- 

 posited before the tooth cuts the gum ; hence 

 cavities are left in the centre of the tooth, 

 which become filled with a dark substance, 

 composed of the animal's food. — Blumenbach. 



Why are bullets sometimes found imbedded 

 and concealed in ivory tusks 7 



Because they have been lodged there by 

 the muskets of the hunters ; and as the tusks 

 are continually growing during the animal's 

 life, the bullet becomes surrounded by new 

 layers of ivory, while no opening exists be- 

 tween it and the surface, to account for its 

 entrance. 



Why does the dog, while changing its 

 teeth, appear to have the canine teeth 

 doubled ? 



Because the permanent ones cut the gum 

 before the old ones have fallen out. 



THE STOMACH. 



Why are certain animals called ruminat- 

 ing '.' 



Because they first imperfectly chew and 

 swallow their food, and subsequently return 

 it through the oesophagus or gullet, in small 

 quantities at a time, to the mouth, there to 

 be thoroughly masticated, and then swallow- 

 ed a second time. 



Why do certain animals ruminate? 



Bec.'uise, it is supposed, of a voluntary 

 power i^i tlie (rsophagus; and, indeed, tlio 

 influence of will throughout the whole pro- 

 cess, is iucontestible. It is not confined to 

 any particular time, since the animal can 

 delay it when the paunch is quite full. Blu- 



