1 882.] Botany. 47 



plant life which had to be met," by a special development, instead 

 of affording a period of needed rest. In fact, it begins to look as if 

 the old notion of the need of rest by a plant would have to be 

 abandoned, or at least very greatly modified. One of the most 

 suggestive things brought out in these experiments is the blight- 

 ing effect of the light from the naked electric light. Plants so ex- 

 posed became shriveled and scorched, while those situated nearer 

 to the light, but having a sheet of glass interposed, were not so 

 affected. 



Botanical Notes. — In Professor Parker's lecture on " Biology 

 as an academical study," published in Nature, there is a most ex- 

 cellent denunciation of the teaching of botany and zoology as 

 mere classificatory sciences, and a strong plea for the " laboratory 

 method," which he properly urges for not only the college but 

 for the high school also. " What," says he, " would be thought 

 of a mathematical teacher who relied entirely on lectures, and 

 never dreamed of insisting that his pupils should apply what he 

 had taught by working out examples for themselves ? Or what 

 of a teacher of art who ignored the necessity of making his stu- 

 dents draw or paint ? Every one sees the necessity of practical, 

 and the uselessness of exclusively theoretical teaching in these in- 

 stances, yet the fact is generally ignored that the case is precisely 



the same with scientific subjects." A good service has been 



rendered by the editor of the American Monthly Microscopical 

 Journal in the publication in his journal of the Rev. W. Johnson's 

 V Introduction to the study of lichens." Several wood-cuts help 

 to make the matter so clear that the beginner need have no 

 trouble in taking up the study of these very interesting plants. 

 Mr. W. H. Leggett has seen reasons for suspecting cleisto- 

 gamy in the common purslane ( Portulaca oteraceaj, and asks in 



the October Torrey Bulletin for confirmation or disproof. As 



showing the incomplete state of our knowledge of the plants of 

 the world, it is significant that seven new species of British lichens 

 are described in Grevillea for September. If species are discover- 

 able at that rate in a country which has been so diligently worked 

 by collectors, what may we not look for in the world at large ! 

 - Wm. Trelease has been studying the nectar glands upon the 

 leaves of Populus, and finds that they appear as a rule only on the 

 nrst half dozen leaves of each shoot in early spring. After a long 

 series of careful examinations, the results of which he records in 

 the November Botanical Gazette, he concludes that these glands 

 are protective indirectly by attracting ants, ichneumonids and 

 lady-btrds, which in turn serve to keep off many harmful insects 



and larger animals. From a study of the flora of Madagascar. 



J. G. Baker ventures in the Journal of Botany to estimate the 

 number of species of flowering plants alone at from four to five 

 thousand, a remarkably high number when we consider the limited 

 area covered by it, viz : 228,573 square miles, or a little more 



