466 BOTANICAL GAZETTE [JUNE 
of microscopic technology, and it remained for the authors of the Enzyklopadie 
der mikroskopischen Technikt to make the attempt to provide a comprehensive 
treatise, in which the whole field of microscopic investigation would be ade- 
quately treated from the technical standpoint, and in which, in addition, the 
chemical and physical properties of the countless reagents employed would 
receive attention. 
The first edition of this work appeared in 1903, and the recent publication 
of a second edition indicates sufficiently well how great was the demand for 
such a book. This new edition has been the subject of a thorough revision, 
bringing all articles up to date and adding many new articles and illustrations. 
At the same time, a number of articles have been dropped, and others so 
shortened that the new edition only exceeds the first by some 80 pages. The 
arrangement of the articles is alphabetical, as the title indicates, and in each 
case the most significant word has been chosen as the initial word of the title 
of the article on a given topic. Synonyms appear in the proper alphabetical 
order, reference being made in each case to the name under which the descrip- 
tive article may be found. Much help in locating the various methods Is 
also given by the excellent authors’ index at the end of the second volume. 
fter each article numerous references are given which help to enhance the 
value of the work. ‘ : 
It is to be regretted that more attention has not been devoted to micro- 
chemical methods. For example, for the microchemical detection of iron In 
tissues only MACALLUM’s older method of treatment with ammonium sulphide 
receives attention, and no mention is made of his iater methods of unmasking 
organic iron by means of acid alcohol, nor of his methods of distinguishing 
between organic and inorganic compounds of iron. The methods for the detec- 
tion of potassium and of chlorides are not considered at all. Ina work of such 
scope, however, it is inevitable that each investigator working in a special 
field will find certain omissions and defects, but these are of minor importance 
when one considers the immense wealth of material which the book offers to the 
working biologist.—R. R. BENSLEY. 
Ancient plants 
During the last decade paleobotany has become a transformed subject. 
and the 
P., USE, R., Mossr, M., Rosrn, H., WEIGERT, K 
*Enzyklopiadie der mikroskopischen Technik. Herausgegeben von EaRLICcH, 
’ E <. 2. Auflage. Bd. 4. PI 
Bd. II. pp. 680. Berlin und Wien: Urban & Schwarzenberg. 1910. M 5° 
