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A Text Book of General Lichenology. With descriptions and figures 
of the Genera occurring in the Northeastern United States. 
By Albert Schneider, M.S., M.D. Willard N. Clute & Co., 
Binghamton, N. Y. 1897. : 
There has been a demand for years for a text book on lichens 
and, though valuable contributions have been made from time to 
time, there has been no complete or general work. In Tucker- _ 
man’s life-work we have aclassic guide for the learned; but even 
the experts admit that the technical difficulties of the “ General — 
Synopsis” defeat its end, for the amateur student at least. 
The well printed and copiously illustrated volume on the sub- 
ject with Dr. Schneider has just brought out is far from popular, 
but it is clear, terse and to the point, and will prove a practical — 
working hand book for those botanists or amateurs that desire to — 
take up the study of these plants. 
The historical sketch of the development of the study of 
lichenology is the best, we believe, that is to be obtained in Eng- | 
lish. From it one gathers a fair conception of the battles of hy- 
potheses fought in the European laboratories for the past hundred 
years or so, and comes away with a clear idea of the most modern ~ 
views upon symbiosis and the morphology and physiology of the: 
lichens. ae 
With reference to the author’s idea that the spores are not ren 
productive organs, we fail to see that his arguments win his point; 
for the reason that a lichen spore does not develop a lichen is that 
it does not find a suitable host. In laboratory work characteristic 
growths of other forms of parasitic life cannot be obtained for — 
similar reasons. 
The teachings of Reinke are strong in the systematic part of 
the work, and due attention has been given to the algae. : 
The illustrations have been well drawn and, though somewhat 
schematic, are a valuable addition to the volume, which is in 5° 
many ways to be recommended as a practical text book. 
S. E. J. 
