262 Analytical Notices of Books. 



Vaucher, a species of Conferva, which has within the last twenty years 

 been repeatedly stated, on the authority of very respectable observers, to 

 produce sporcB endowed with animal life, and capable of reproducing 

 the plant from which they derived their origin. These statements are 

 confirmed, as far as the casual and not very guarded observations here 

 <ietailed can be regarded as confimatory of so delicate a fact, by the testi- 

 mony of M. Unger, the authour of the present paper; who has seen the 

 >animated particles separate from the coniocystcz of the parent plant, 

 perish in the course of a few hours by a conversion into globules of vege- 

 table matter, which sent forth processes and became, after a few days 

 growth, ConfervcB perfectly similar to the individual from which the 

 supposed animalcula were originally produced. In this new plant he 

 has seen the coniocystcs again form, and the animalcula again separate, 

 the whole cycle of animal and vegetable existence being completed in less 

 than twelve days. Such is the substance of M. Unger' s observations : but 

 we repeat that they do not appear to us to have been made with sufficient 

 minuteness, or with that degree of caution which is absolutely necessary 

 lo ensure success in so delicate an investigation. At all events we cannot 

 <;onsider this extraordinary fact as by any means clearly ascertained and 

 3)laced beyond the reach of doubt. 



Histoire Naturelle des Mammiferes: par MM, GeoffroY' 

 Saint Hilaire et F. Cufier. Livraisons, S7eme et 

 bSeme. 



NoTWiTHSTANDiNO the long delay which has taken place in the ap- 

 pearance of the present numbers of this valuable and important work, 

 thdr contents afford nothing of high or peculiar interest. Their novel- 

 ties are limited entirely to species, and even these are not advanced with- 

 out the expression of some doubt as to whether the two animals which 

 are so represented may ultimately prove entitled to the rank which has 

 been assigned to them provisionally. The first of these is an Antelope, 

 to which the appellation of Kevel gris is affixed, and which is closely 



