figures illustrating the species follows each description and always includes 
the record of the exact specimen used in making the drawings, a practice 
deserving to be universally adopted. 
From the systematic view point this effort of Mr. Roth rounds out and 
brings up to date in accessible form for use, the achievements on European 
mosses since Schimper’s monumental task on his Bryologia Europaea. The 
plates are necessarily crowded and are largely restricted to drawings of 
microscopic characters, so as to bring the work within the compass of reason- 
able accessibibility. 
The noteworthy feature of Mr. Roth’s work is not so much in his contri- 
bution to systematic Bryology, which is considerable, as it is in his primary 
motive, steadfastly followed throughout, of tracing the intimate relation of 
the moss flora of the earth to the general economy of nature, their influence 
on and relation to the soil, to moisture and especially to forests. This fact 
will stand out more strikingly after a careful perusal of the general discus- 
sion introducing the subject, covering pages one to ninety-two of the first 
volume. 
In this introductory treatment the author disposes first of the anatomi- 
cal structure of the mosses, presenting in well sustained discussions the 
facts of protonema, moss stem, moss- leaf, inflorescence, sporogone, propaga- 
tion and distribution. And so far he is in full accord with the treatment of 
the subject in other comprehensive works on mosses. It is, however, in the 
closing essay on the general subject, covering pages sixty-two to seventy- 
eight, that Mr. Roth departs conspicuously from the single purpose of the 
systematist, in that he shows convincingly the importance and the signifi- 
cance of mosses in the economy of nature in agriculture, and especially in 
forestry. Something of a fair conception of his claims for mosses may be 
gained from thb twelve theses he expounds in this striking essay; i. 
Mosses diminish the danger of inundation. 2. They hinder gullying of the 
soil and aid in the steady flow of springs by increasing the quantity of water 
derived from condensation and seepage. 3. They preserve the porosity of 
the soil. 4. They maintain and increase the humidity of the soil. 5. They 
aid in the formation of humus and so increase the depth of good soil. 6. 
They introduce the decay of rocks. 7. They effect an equalization of the 
temperature of the soil. 8. They may be used as bedding material by the 
agriculturist, 9. They constitute a useful index of conditions in the forma- 
tion and improvement of meadows. 10. They likewise furnish to the fores- 
ter a helpful index of climatic conditions favorable to different forest trees. 
The treatment of this point closes with these words, “ If the forests officials 
who in recent years traveled all over North America for the purpose of 
studying the then existing forests had only brought back with them the 
principal representatives of the moss vegetation found in the forest regions 
traveled by them, we would be much more easily able to form a judgment 
concerning the adaptability of the several forest trees to our (German) 
conditions ” 11. Mosses protect forest trees against the effects of too great 
cold. 12. On the part of man some mosses are used in the industries and in 
the domestic life. 
