1909] CURRENT LITERATURE ^5 



t 



to support this conclusion. I see no grounds,, however, for concluding that the 

 effect is upon the digestive enzymes rather than upon some other mechanism of 

 the protoplasm. 



Kinzel's attention has been largely centered upon the effects of rays of different 

 refrangibility. Heinricher 16 early found that the red end of the spectrum was 

 most effective in Veronica peregrina. Kinzel's results indicate that this is 

 generally the case. Among different species, however, there is a great variation in 

 the relative effectiveness of various rays. Green is by far the most effective with 

 Nicotiana, while with Veronica yellow gives the greatest stimulation. Kinzel 

 finds the blue rays least effective; in fact they often cause marked retardation. In 



cases 



rmination than darkness. Kinzel comments upon the 

 general retarding effect of blue light, while Heinricher later points out that in 

 the seeds of Pliacelia tanacetifolia which are retarded in germination by white 

 hght, blue markedly stimulates germination. 



Many of the "light-loving" seeds demand a considerable period of rest after 

 harvest, during which they become thoroughly dried out. In Veronica bellidioides 

 three and one-half months was the most effective period. In the short-lived seeds 

 Drosera fifteen hours of drying in the laboratory- best effected their "after-ripen- 

 H- Heinricher says, "On the whole the experiments indicate that the 



upon 



upon 



and 



must T Cr ° r SeVera1 ' Fina lly, even the moisture content of the air during storage 



com I C C ° nsidered M a factor - It is evident that the conditions are extraordinarily 



tinner 1 ! 1 * at conformi ty of results is to be expected onlj 

 ll °n of all these factors." 



under 



light 



Heinricher 



of , J? m ° r f ° ften conne cted with their phyletic relationships than with likeness 

 01 ecolo gIC al habit. 



tors slj Id t0 thC reviewer that in cases wh ere evident coats appear, the investiga- 

 sion nf U W ° rk With coat - f ree seeds to make sure that the coats by partial exclu- 



«onof 



%ht ma^lf*' SaItS ' ° f eVCn Water are not hindering germination. In such cases 



germin 



Proble 



B 



™em wili aIS ° CVident ' from the vari able results, that the real solution of the 

 housed b T" 6 fr ° m ) earnin 8 the particular dormant process in each case that 



y light. This oufrht tn K*» r^cei'ki^ ;~ „.'<»„r ^r t\,* m-*»at advance beine 



Inad e in I "ugni ro oe possible in view ot tne great aavancc ucm 6 



d «»uuid a" ° wled § e of the catalytic nature of protoplasmic activity, but it will 



ie proDiem trom other points 



Wm. Crocker. 



16 Hedj 



Gesells. 1 * . ^ HER ' E '' Ein Fal1 beschleunigendes Wirkung. Ber. Deutsch. Bot. 



3H. 1899. 



