Marvels oj Pond-Life. 27 



adduces important reasons for associating them ^vitll 

 the insects. 



Leaving zoologists to settle their position, we may 

 remark that the Kotifers form a very numerous family, 

 presenting very great diversities of structure, some of 

 the most interesting of which we shall meet with in the 

 course of our rambles ; but they all possess a gizzard, 

 which, though differing in complexity, is throughout 

 formed upon the same principle, and that we must now 

 explain. 



We have called the masticatory apparatus of the 

 Rotifers a gizzard ; but Mr. Gosse, who has done most 

 to elucidate its structure, contends that it is a mouth ; 

 and in some species it is frequently protruded, and used 

 like the mouth of higher animals. Taking one of the 

 most typical forms of this organ, and drawing our illus- 

 trations from Mr. Gosse^s admirable paper in the 

 "Transactions of the Royal Society,^' we may describe 

 it, when completely developed, as consisting of three 

 lobes, having a more or less rounded form. The 

 eminent naturalist we have named calls the whole organ 

 the mustax, and states that it is composed of dense mus- 

 cular fibre. The tube which leads down to it he 

 designates the " buccal (mouth) funnel,^' and the tube 

 that issues from it, and conveys the food to the digestive 

 sac or stomach, he calls the oesophaf/us, in conformity 

 with the nomenclature applied to creatures whose 

 mouths are in the usual place. Inside the mouth - 

 gizzard are placed two organs, which work like ham- 

 mers, and which Mr. Gosse therefore names mallei. 

 The hammers work against a sort of anvil, which is 



