CHAPTER V. 



THE SPONGE THE HYDRA. 



THE animals accounted lowest in the scale of 

 existence, are by no means the least wonderful of 

 the works of the Creator. Indeed, in some respects, 

 they excite more than common interest, as discovering 

 to the reflective mind the utmost simplicity of 

 organization, conjoined with animal, not vegetable 

 life. Their structure is surpassed in intricacy by 

 that of many vegetables, perhaps by most ; yet, 

 simple as it is, it is only the first of a series of 

 gradations, which conducts us to the highest orders 

 of animated nature. 



Naturalists place a group or assemblage of animals* 

 lowest in the scale, in which no distinct nerves are 

 to be perceived. They are, with few exceptions, 

 tenants of the water. They consist essentially of a 

 gelatinous substance, the solid constituents of which 

 bear but a trifling proportion to the fluid. This 

 gelatine is sometimes unsupported by any kind of 

 framework ; but generally it either invests, or is 

 contained in a horny or a calcareous support, which 

 is elaborated from it, and varies greatly in outward 

 form and appearance. 



Though no nervous fibres have been detected, it 

 * Acrita. 



