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CURRENT LITERATURE. 
Microseopical methods. 
American botanists are much indebted to Dr. James E. Humphrey 
for translating and to Messrs. Henry Holt & Co. for publishing a 
very valuable work on botanical microtechnique. The work was writ- 
ten by Dr. A. Zimmermann,’ privat-docent in the University of Ti- 
bingen, and published in Germany last year. 
It is rare that such a wealth of detailed information is condensed 
into so small space. The general methods of observing, staining and 
mounting specimens are first taken up, followed by microchemical 
methods, methods for investigating the cell wall and the various cell 
contents, some account of the preparation and examination of bac- 
teria, and a list of literature and an index. The variety of substances 
which may now be detected microchemically is astonishing. Over 
one hundred compounds or groups of compounds are treated in the 
third of the volume given to microchemical methods. An equally 
great number of substances are dealt with in the next third of the vol- 
ume, relating to the cell wall and cell contents. 
In using the work some disappointment will be felt now and then 
on account of the brevity with which many of the topics are treated, 
but this fault, arising from the multiplicity of topics, is partly atoned 
for by the careful citation of literature, the page as well as the volume 
being named. 
Nearly two hundred authors are mentioned in the enumeration of 
literature, and two or three times as many distinct works. The text 
has not, however, been merely compiled from these abundant data, 
but the author has tested a large part of the methods, and given his 
views of their value, often suggesting excellent modifications. 
The work of the translator has been well done. He has taken oc- 
casion to add a few items to the text, the most important being in re- 
gard to celloidin imbedding. He has also added to the appendix a 
Series of very useful reference tables, notably a table of specific gravi- 
hes and percentage composition of a few common solutions and 
De Vries’ table of “isotonic coefficients” comparing the water-absorb- 
'ng power of six great groups of compounds. The author has also 
res. Trans. from the German by James Ettis HUMPHREY. 
figs. 63. New York: Henry Holt & Co. 1893. $2.50. 
