99 
Plant Dissection. J.C. Arthur, C. R. Barnes and J. M. Coulter. 
(8vo., pp. 256, Henry Holt & Co., New York, 1886.) 
A useful guide for the study of a few common plants. The 
authors have modelled the work after Huxley and Martin’s Ele- 
mentary Biology, omitting however, all reference to physiology, 
and prefixing an introduction giving directions for the use of 
instruments and reagents; methods of cutting, staining, mounting 
and drawing objects under the microscope. The last point is 
illustrated by two plates. The work is outlined for the follow- 
ing plants: Protococcus viridis, Oscillaria tenuis, Spirogyra 
quinina, Cystopus candidus, Microsphera Friesti, Marchantia 
polymorpha, Atrichum undulatum, Adiantum pedatum, Pinus 
sylvestris, Avena sativa, Trillium recurvatum, and Capsella 
Bursa-pastoris. Frequent references as foot-notes and a glos- 
sary, complete a very convenient little guide for the student 
both inthe laboratory and at home. It embraces a wider field 
than Bower and Vine’s Practical Botany, but goes less into detail. 
Problems relating to the Giant Trees.—A new study of some. C. 
B. Bradley. (Lippincott’s Magazine, 1886, pp. 305-316.) 
An interesting discussion of the cause of the restricted oc- 
curence of Sequoia giganiea, in which the writer concludes that 
the seeds germinate only when they reach the actual earth, 
being unable to grow in the humus layer which deeply over- 
spreads the ground beneath the trees. The ease with which 
gardeners succeed in raising Sequoias from seed in ordinary soil 
is cited as an argument in favor of this hypothesis. Mention 
is made of the great abundance of seed produced. Each cone is 
said to contain from 175 to 200 sound seeds, so that the total 
annual product of even a single tree must be enormous. Were 
Mr. Bradley’s idea borne out by other observations it would 
seem that the extinction of these noble trees might easily be 
prevented and their distribution as easily widely increased. 
Prodromus Flore Adventicie Boreali-Americane. Th. A. — 
Bruhin. (Verhandel. der. K. K. zool. botan. Gesellsch. in 
Wien (1885), pp. 387-450; also reprinted.) ; 
A preliminary list of adventive, naturalized and cultivated 
plants of North America, compiled mainly from the writings of 
Pickering, Wood, Gray and Chapman, with observations of the au- 
