NOTICES OF BOOKS AND MEMOIRS. 153 



peculiarities presented by the different species, supplies the place 

 of a technical generic character. 



An Introduction, of which instalments are given in the half- 

 dozen parts before us, and of which the extent is not yet 

 apparent, will be extremely useful to the general reader, whom we 

 may suppose to be entirely ignorant of fern structure ; and to whom 

 therefore an intelligible account of the nature of the several parts 

 of which a fern is composed is of great importance as a means 

 towards the understanding of the book. 



Thus it will be seen that the text comprises—first an intro- 

 duction explanatory of the structure of ferns in general, in- 

 cluding a sketch of their geographical range, and passing on to 

 the main features of their cultivation ; and secondly, an account 

 of the peculiarities and variations of each genus, and a full 

 description of the species which form the subject of the illus- 

 trations. This is clearly and accurately written, and sufficiently 

 attests that the author has the subject well in hand. The plates, 

 which, as we have said, are well-drawn and accurate in themselves, 

 have the demerit in some cases of presenting reduced figures of the 

 originals, a style of portraiture we should recommend the 

 publishers to abandon, if possible, in the case of the portions yet 

 unpublished. 



The book is very nicely got up, and is from this point of view 

 highly creditable to all concerned, since faithful representations, 

 accurate descriptions and observations, and tasteful production are 

 combined, and the result will be to present to the public a very 

 elegant and useful volume. T. Moore. 



Isontributiojis a la connaissance des organismes qui peiivent se trouvcr 



dans la Mere et le vioiit de biere et y rivre. Par Emil Chr. 



Hansen. 



This paper commences with some " Kecherches sur les 

 organismes qui, a differentes epoques de Tannee, se trouvent dans 

 | air a Carlsberg et aux alentours, et qui peuvent se developper dans 

 ie mout de biere." The nourishing liquid selected was clear beer- 

 yort with the hops added, and it was sterilised by prolonged boiling 

 m large-mouthed flasks closed with a layer of filter-paper. Each 

 flask was of one quarter of a litre capacity, and was usually about 

 two -thirds filled. They were then exposed in different situations 

 m *^e neighbourhood, such as a seat in the Carlsberg garden, 

 various parts of breweries, under cherry trees and gooseberry 

 Joshes, and a summer-house and vinery. It would take too long 



to 



that a considerable 



™ go into the results in detail ; suffice it to say 

 uitterence was observed in the growth induced in different localities, 

 he experiments were continued into the winter in order to judge 

 01 the effect of frost upon the growth. It was found that at 

 a minimum temperature of -7° C, and a maximum of 2°, all trace 

 wccharoviyces was sought for in vain, but that Microbacteria, 

 ^ncillium ylaucnm and cladosporioides, and Mucor stolonifer could 



The organisms, however, take a longer time to develop in 



x 



