48 BOTANICAL GAZETTE. 



(clay) of cle;ir weather. Carrying this calcuhitiou further we are impressed with the 

 important i^art that groves and forests phiy iu preserving the humidity of the ai)'. 



Nates on Trees (ind Tree-Plaiitiwj, by C. S. Sargent.--This paper is considered as 

 supplementary to one contributed by the aullior to liie Ileporl of the Board of Agricul- 

 ture for the year 1875. In the latter he considered the value of the white ash, white 

 and Scotch pines, European elm, white oak, the hickories, white willow, sugar-maple, 

 and European larch, for New England plantations. The present paper adds to the list 

 the red or Norway pine, the wild black clierr}', the American cork, or Western rock 

 elm, and the Ailanthus. The last mentioned tree, the writer thinks, has been at once 



the subject of more undeserved praise and more ignorant and foolish abuse than any 

 other tree. The pai)er is well worth a careful perusal. 



Boiamcdl Directory for America, 1878. — Mr. W. II. Leggett has done a very great 

 favor to Botany in publishing this very full directory. It contains the names of nearly 

 1,000 American l)otanists and is invaluable to botanists desiring information or ex- 

 changes, to say nothing of those of us who publish for the botanical Fraternity. The 

 tliird i)arl, relating to libraries, herbaria, gardens and catalogues of value, will prob- 

 al)ly be ready about the beginning of May. The price is 40 cents for one copy; three 

 copies for $1.00; twelve copies for $8.00. Address Wm. II. Leggett, 54 East 81st street, 

 New York City. 



TridisKctions (if the Massachusetts Horticultural tSocieti/, 1877, Parts I and II. — Be- 

 sides reports of committees and prizes offered antl received, we find some very interest- 

 ing botanical information. "Fertilization and cross-fertilization" and "Injurious and 

 other Fungi," are given in the form of lectures and tiien discussed. 



Sur Vexistence de Races Pliysiologiques dans les EJspeces Vegetales a Petal sj)oiUane, 

 par M. Alph. DeCandolle, January, 1878 — M. DeCandoile has published before some 

 observations on the same subject. MM. Naudiu and Kadlkofer experimenting at Col- 

 lioure and Munich have reached results contirmatory of those published by M. De- 

 Candolle. In the present paper the author brings together the two sets of experiments, 

 and after having shown the results, adds some remarks upon the physiological ditier- 

 euces in vegetables of the same form, and the condition of the science in respect to the 

 questions of the origin of these ditlerences. The modification of species under the in- 

 fluence of climate is a very important ({uestiou, and the author considers the observa- 

 tions too few as yet to be able to hazard many deductions. The method of experiment 

 was as follows: Seeds of the same species were obtained from as widely separated lo- 

 calities as possible, and subjected to the same treatment. The t^mes of their blooming, 

 and their vai'ious sizes were noted and comparecl. The results show quite a diversity 

 both in the time of blooming and iu the size and vigor of the plants. The plants ex-, 

 perimented with by M. DeCandolle were a dozen in nuniber, but only two gave satisfac- 

 tory results for comparison, Venecia oulejaris and TrifoUuiib repens. Of the plants ex 

 perimented with Ijy MM. Naudin and Kadlkofer, several were ruled out as being unsat- 

 isfactory, leaving only two that could be properly used. Calendula, uroenis and tSo/ichus 

 oleraceus. The two following conclusions are deduced from the experiments: I. That 

 some seeds of the same species coming from distant countries, sowed together, exposed 

 to the same intiuences, do not produce individuals that grow in absolutely the same 

 manner. II. That iu certain sj)ecies, notwithstanding a similarity of external forms, 

 the ditt'erence from the vegetaticm of tlie originals is better characterized than in others. 



Eapport sar le jiirdin cxperiinentol de M. Jordan, par Alph. DCJ., February, 1878. 



4 



