^46 FOURTH REPORT — 1834. 



quiry in particular which forcibly suggests itself. Is there any 

 similar complexity of structure, anything approaching to an 

 alimentary sac or stomach, in those monads, which, it is asserted 

 by so many observers, become fixed after a time, and transformed 

 into Confervce ? The determination of this point will go far 

 towards determining the true situation of a host of ambiguous 

 genera at present hovering between the two kingdoms, and hav- 

 ing almost equal claims upon the notice of the zoologist and 

 botanist*. 



IV. Concltcsion. 



In the preceding pages I have endeavoured, though I fear 

 very imperfectly, to give a condensed view of the principal re- 

 searches which have been made of late years in Zoology, at least 

 such as have tended to throw light upon the affinities of animals, 

 and thereby to advance our knowledge of the natural system. It 

 was my original intention to have proceeded here to the con- 

 sideration of some other parts of the subject, such as the state 

 of our knowledge with respect to the actual number of species 

 in the several classes, and also with respect to the zoology of 

 particular coimtries. The former, however, is rendered un- 

 necessary from the appearance of an article in the Edinh. New 

 Philos. Journ. of last year f, expressly devoted to this branch 

 of inquiry. The latter would afford an opportunity of alluding 

 to several valuable works which have been recently published in 

 this and other countries, some containing many new and inter- 

 esting forms of importance to the science in general. But the 

 length to which this Repoi't has already been extended precludes 

 mj' entering upon this subject. Considered also in connexion 

 with that of the geographical distribution of animals, it would 

 furnish ample materials for a separate communication. I shall 

 therefore, in conclusion, merelj'^ offer a few remarks connected 

 with the further progress of zoology, and its advancement in 

 this country in particular. 



(1.) Its general progress, viewing the natural system as the 

 true object of the science, and considering the very imperfect 

 knowledge we have of this system at present, must clearly de- 

 pend upon the discovery of new forms, and a more thorough in- 

 vestigation of those already known to us. If the former be ne- 

 cessary in order to supply some of the numerous links that are 

 yet wanting to complete the chain of afl&nities, the latter is not 



• For further information respecting these anomalous productions, the reader 

 is referred to the article Arthroidees in the Diet. Class. d'Hist. Nat., and to the 

 articles Nemazoaires and Zoophytes in the Diet, des Sei. Nut. 



t No. 30, for July 1838, p. 221. 



