29 
Weeping Spruce—The. Thomas H. Douglas (Gard. and For. v. 591). 
With illustration of Picea Breweriana. 
Wistaria Sinensis—The. Anatomy of the Stem of. Carlton C. Curtiss 
(Journ. N. Y. Micros. Soc. viii. 79-89; three plates. Re- 
printed as Contrib. Herb. Col. Coll. No. 28). 
Mr. Curtiss describes at length the anatomy of the stem of this 
vine, with especial reference to the secondary layers of bast which 
are formed in the growth of old stems at intervals of several 
years and become covered by the succeeding layers of wood. The 
material which called especial attention to these studies was re- 
ceived some time ago from Mr. B. Heritage, of Mickleton, N. J. 
Reviews of Foreign Literature. 
Fossil Plants as Tests of Climate. A. C. Seward. (Pamph. 
8vo., pp. 151; Cambridge Univ. Press, London, 1892. New York, 
Macmillan & Co.) This is the Sedgwick prize essay for the year 
1892, and in it the author has endeavored “to consider plants as 
the thermometers of the past,” in which effort he has succeeded in 
bringing together practically all important references by botanical 
and geological writers on the subject. Plants in spite of their 
meagre palzeontological remains, as compared with animals, have 
always been considered as the more trustworthy indices of climatal 
changes, as they are unable to migrate with the same ease as 
animals in the event of a change in temperature. They must 
either perish entirely or else gradually adapt themselves to the 
changed environment. 3 
An introduction and historical sketch precedes the subject 
matter proper, after which follow chapters on plant distribution, 
Arctic vegetation, influence of external conditions upon the macro- 
Scopic and microscopic structures of plants, annual rings in re- _ 
cent and fossil plants, Arctic fossil plants, Carboniferous Period, 
Pleistocene plants and concluding remarks. 
The principal question to be solved has always been whether 
the evidence warranted the assumption of a uniform climate 
throughout the world in past geological ages or whether there 
___ Were temperature zones as we recognize them to-day. The general a 
ce ig view of the Ribot undonbendix 4 indicates a uniform tem- 
