COMPARISON BETWEEN AXI.MALS AND PLANTS. 243 



The sponge also belongs to this class of strange animal substances -, 

 it consists of a fibrous mass, containing a jelly-like subst^ince. 

 which when touched, discovers a slight sensation, the only sign of 

 Ufe manifested by it. There are many species of sponge; those 

 most valued in the arts are found in the Mediterranean sea and In- 

 dian ocean. Some grow upon rocks, and are found covering the 

 interior of submarine caves. The Spongia parasitica is seen grow- 

 ing upon the back and legs of a species of crab; sometimes as ma- 

 ny as forty individual sponges extend themselves over the crab, 

 impeding the motion of its joints, spreading like a cloak over its back, 

 or forming for its head grotesque and towering ornaments, from 

 which the poor crab vainly attempts to disencuniber itself 



Some species of the sponge grow to a very large size; one has 

 been found in the East Indies in the form of a cup, capable of con- 

 taining ten gallons of water. The fibrous part of the sponge is the 

 skeleton of the animal; the large apertures (see fig. 158, 6,) serve to 

 carry out fluids from within ; while the water by which the animal 

 is nourished, is imbibed by minute pores: this continual circulation 

 of water is one of the most important functions of the living sponge. 



These animals resemble plants in their manner of producing 

 others ; they form a species of germ, like the bud growing upon 

 the stalk; this falls off from the stem, and becomes a perfect animal. 

 If a part of one of these animals is separated from the rest, it Avill 

 itself be as perfect a living animal as was the whole before. A poly- 

 pus can be divided into as many animals as it contains atoms ; 

 some of this order are very properly called hydras, (many-headed.) 

 Besides these, there is another order of animal substances, infmoria^ 

 which appear like a homogeneous mass, having no appearance of 

 any limbs whatever; these are either angular, oval, or globular. 



LECTURE XLVII. 



COMPARISON BETWEEN ANIMALS AND PLANTS. 



In our last lecture, after a glance upwards to the heavenly bodies, 

 we returned to our globe, and considered its various sulDstances ; 

 here we found two classes of bodies, inorganized and organized 

 substances ; the former including minerals, the latter embracing the 

 animal and vegetable kingdoms. We then took a brief view of the 

 animal creation. 



At the head of the animal kingdom, we found man, sufficiently 

 resembling brute animals in his material frame to constitute part of 

 an extensive class, embracing the ape, elephant, and dog ; yet be- 

 tween the lowest degree of intelligence in the human race, and the 

 highest faculties of brutes, there is a fine of distinction marked by the 

 hand of the Almighty, in characters too obvious for doubt. God said, 

 "Let us make man in our own image, and he breathed into him the 

 breath of life, and man became a hving sou.V 



Some writers have attempted to show that man differs only from 

 the inferior order of animals in possessing a greater variety of in- 

 stincts. But however wonderful may appear the instinctive percep- 

 tion of brutes, they are destitute of reason, and incapable of being 



_ Sponge— Manner in which tnese animals are reproduced— Recapitulation— Man at 

 the head of the animal kingdo.'i:— How resembling inferior animals. 



