316 ORDER II. MOLLUSCS. 



adapted to its situation. It is armed with sharp spines, or 

 prickles, which it occasionally erects or depresses; and 

 under the skin is a slimy juice, which it ejects through 

 certain perforations between the rings of the muscles, as 

 occasion requires. It has also breath^apertures along the 

 back, and is furnished with a mouth and an alimentary 

 canal. The latter is always found full of a very fine earth. 



Worms unite both sexes in themselves, at once impreg- 

 nating and being impregnated in their turn. Their eggs 

 are laid in the earth, and become hatched, in twelve or 

 fourteen days, by the genial warmth of their situation. 



During the winter, these animals bury themselves deeper 

 in the earth, and appear in some measure to partake the tor- 

 pidity of the insect tribe ; but in spring they revive, and 

 pursue the universal purpose of propagating their kind. 



As a proof of the simple organization of worms, and 

 their degradation in the scale of being, they are also 

 capable of being multiplied by cuttings. Each section 

 gradually acquires what was wanting to complete its form ; 

 and, in a few months, the minute parts of the original 

 creature attain their natural size and proportion. Thus 

 one of the most seemingly abject of lives is the most 

 difficult to destroy ; and, in proportion to the dangers to 

 which the tribe is exposed, Providence seems to have,, 

 allotted it qualities requisite for its preservation, 



ORDER II. MOLLUSCS. 



ANIMALS of this order are simple and naked; but they 

 are brachiated, or furnished with a species of limbs. 

 There are thirty-one genera, and a great number of species ; 

 some of which, as the medusa, the echinus, and the limax, 

 are objects of particular curiosity to the proficient in 

 natural science. By far the greater part of molluscae are 

 natives of the sea or its shores. In this treatise only a 

 few can be particularised. 



