26 EXPEKIMENT STATION BECOBD. [Vol. 37 



as a selectively permeable membrane. The authors have now studied more 

 particularly the entrance of these solutes Into the .seeds, together mth water, 

 in the hope of throwing some light on the physical causes governing selective 

 permeabilitj'. A preliminary investigation having shown that phenol and 

 anilin solutions enter the seeds in higher concentrations than the solutions 

 in which they are immersed, quantitative experiments were made employing 

 variously concentrated solutions of anilin, phenol, and acetic acid. 



The results are presented in tabular and graphical form with discussion. 

 Pure acetic acid w^as not absorbed by dry seeds. 



The relation between the concentration of various inside solutions and the 

 amount absorbed at equilibrium was also studied, and the results have been 

 tabulated. The various forces involved are fliscu.s.sed. 



Some photochemical experiments with pure chlorophyll and their bearing 

 on theories of carbon assimilation, I. Jorgensen and F. Kidd {Proc. Roy. 

 Soc. [London], Ser. B, 89 (1916), No. B 617, pp. 5^-361. fujs. 2).— The authors 

 have examined certain photoclioniical reactions of chlorophyll observed and 

 hypotheses advanced by previous investigators as a basis for theories of carbon 

 assimilation. Pure chlorophyll was employed in this work as a sol, with water 

 as a dispersion raetlium, and this sol, in contact with different gases in closed 

 vessels, was exposed to light. 



In nitrogen no change occurred in the chnnnogen complex of the chlorophyll 

 molecule. In carbon dioxid (which here bohaved in solution as any other 

 weak acid) phieophytln was produced, but no further change took place in 

 the chromogen complex and formaUlehyde was not formed. In oxygen a yel- 

 lowing, attributed to phaeophytin, was observable, and this was foUowefl by 

 a bleacliing, the latter development being accelerated and the former omitted 

 when alkali was added. Formaldehyde was produced gradually at first, but 

 more rapidly after bleaching was completed. Increasing to a maximum and 

 then diminishing, while acidity increased throughout. It Is suggested that 

 formaldehyde ari.ses mainly from the phytol, which is presumably split olT 

 from the chlorophyll molecule under light and oxygen. 



Aeriferous tissue in willow galls, A. Cosens and T. A. Sinclaib (Bat. Gaz., 

 62 {1916), No. 3, pp 210-225, pis. 3. figs. 5).--The failure of all attempts by 

 varying environment to develop or increa.';c the aeriferous tl.«;.sue where found 

 in certain portions of insect galls is considered to prove that they are heritable 

 tissues. The reinstatement in a gall of vestigial characters of the plant is 

 considered to have an important bearing on the question of gall formation. 

 It is claimed that there is no authentic instance of any organ or tissue in a 

 gall that is new, ontogenetically or phylogentically. to the host in que.stion. 



Improvements in the method for determining the transpiring power of 

 plant surfaces by hygrometric paper, B. E. liHiNGSTON and Edith B. Shrevk 

 (Phint World, 19 (1916), No. 10. pp. 2S7-309). — The authors have given in con- 

 siderable detail the results of several years of work on improvements which 

 are claimed to render field tests of the transpiring power of plants much less 

 arduous and more precise than was formerly the case. These improvements 

 relate to the elimination of repeated field tests over the standard evaporating 

 surface, the substitution therefor of a thermometer reading and a simple arith- 

 metical calculation, the introduction of composite paper slips including two 

 permanent color standards and the use of small desiccators for keeping the slips 

 dry and at air temperature until a test is to be made. Improvements in the 

 standard evaporating surface, and a more uniform cobalt chlorid paper than 

 any previously employed. 



Germinability tests with seeds of Lepidium sativum under diverse condi- 

 tions, P. Le&age {Compt. Rend. Acad. Set. IParis], 163 {1916), No. J8, pp. 466- 



