Nova Acta Academies Naturee Curiosorum. 261 



take on a disposition to repeat itself, and the animal at length becomes 

 compounded of a series of joints, each of which is a repetition of the 

 whole. The JVematoidea again pass into the true Annulata, the imiform 

 character of the joints being finally lost in the union of several into 

 distinct segments, of various forms, and each endowed with its own pro- 

 per and peculiar functions. The same graduated scale of developement 

 from the analogous form among the Protozoa, to the most perfect 

 animals of their respective type, is also followed up by our authour 

 through the two grand divisions of Radiatd and Mollusca; and the 

 branches which each tjrpe gives off towards its fellows are cursorily 

 noticed. Other tribes of animals are again spoken of as forming inter- 

 mediate series between two of the principal types; as for example the 

 astomous ParamcedcB are indicated among the Protozoa as intermediate 

 between Annulosa and Radiata, and as forming the commencement of 

 a series, which is continuous with the Trematodce, the latter leading 

 through the Planarics to the true Leeches, and thus coimecting them- 

 selves with the Annelida. 



In this necessarily rapid and consequently imperfect sketch of a few 

 btily bf the leading points treated of in the very remarkable series of 

 papers now before us, we have found it impossible to oifer even a faint 

 outline of the mass of facts and reasonings which it embraces : it can- 

 not therefore be expected that v«re should enter into a discussion of the 

 authour's views, or a critical examination of the theory on which they 

 are founded. We must, however reluctantly, rest contented with hav- 

 ing directed the attention of our .readers, to the volume in which they are 

 contained; and with observing that, although fairly open to many and 

 weighty objections, they are still highly deserving of that consideration 

 which is always due to new and original views, when those views are, 

 as in the present instance, based on apparently accurate, and certainly 

 careful and minute, investigations. 



The only remaining paper at all connected with zoology is one which 

 hardly falls within our province," but which, relating as it does to a sub- 

 ject of no little interest, it may be as well not to pass over in silence- 

 This is an account of the metamorphoses, or, as we should rather be in- 

 clined to say, the supposed metamorphoses, of the Ectbsperma clavata of 



