BOTANY. 



943 



Airragr jx'rrcntiK/i' of moisture m forest trees. 



The influence of humidity on the formation and development of stomata, 

 G. Mariana {Separate from Atti Inst. Bot. Univ. Pavia, 2. ser., S {lOOJ), 2jp. .32). — 

 Studies are reported on the effe(;t of humidity on the development of stomata on the 

 cotyledouarj' leaves of a number of plants such as buckwheat, beets, radishes, balsam, 

 white lupine, crimson clover, plane tree {Acer psewloplatanus) , gourds, etc. Accord- 

 ing to the author, humidity favors the development of the superficial area of the 

 cotyledons, and for a given area there are usually fewer stomata per unit of surface 

 of those Cf^ityledons produced in moist atmospheres. The development of the epi- 

 dermal cells in the cotyledonary leaves follows the same rule. In general a humid 

 atmosphere favors the formation of stomata, although not increasing their number. 

 Humidity and drought were found to have no effect in influencing the relative 

 numl)er of stomata on the two surfaces of the leaves. 



The effect of concentration of solutions on the respiration of plants, AV. 

 Palladine and A. Komleff {Rei). G.'n. Bnl., 14 {1902), No. 16S, pp. 497-516) .—T\\q 

 effect of different concentrations of saccharose on the respiration of a number of 

 different ])lants is reported. The results obtained show, so far as the respiratory 

 energy of the jilants was concerned, that the respiration of the plant was highest 

 when solutions of average concenti'ation were used. Tf stronger or weaker solutions 

 were employed there was a marked falling off in the respiration of the plants. The 

 effect of sudden changes in the strength of solution showed that changing etiolated 

 leaves of beans from a strong to a weak solution resulted in a rapidly increased 

 respiration, while transferring them from a weak to a stronger one diniinislied the 

 respiratory energy. 



The influence of mineral salts on the respiration of plants during- g-ermi- 

 nation, S. Krzesnieniewski {Separate from Bui. Acad. Scl. (.'racovie, 1902, pp. l-41,pls. 

 2; atis.hi, Bot. f'enfbl., 90{1902) , JVo. 19, pp. 525, 526). — After reviewing the investiga- 

 tions of others relating to the action of certain minerals on germination the author 

 gives a report of his investigations on the influence of the various mineral salts con- 

 tained in the Knopp solution on the germination of radish seed. It was found that 

 the respiration of plants began at the time the seed began to swell and increased 

 quite rapidly as soon as the radicle began to appear. The proportion of carbon 

 dioxid to oxygen was equal to 1 at the beginning of the experiment but it rapidly 

 diminished as the respiration reached its maximum. The different salts which 

 entered into the composition of the Knopp. solution did not affect the respiration 

 in the same manner. The potash salts were most active and where these were 

 omitted the respiration was very low. Practically the same results were ol)tained 

 with the nitrates. 



The effect of temperature on carbon dioxid assimilation, G. L. C. Matthaei 

 {Ann. Bot., 16 {1902), No. 64, jjp. 591, 592). — An abstract is given of a paper pre- 

 sented before the British Association for the Advancement of Science, which shows 

 the effect of temperature on the assimilation of various leaves. A number of leaves 



