1890 FLASHING LIGHT ON PLANTS 219 



emanated. Perhaps we miglit arrange to meet some- 

 where soon to have a talk over the expediency of 

 such a debate at all, and the lines on which, if held, it 

 should run. Of course, physiological selection would 

 be carefully kept out. My object would be to show 

 the prime importance of natural selection as a theory 

 which everywhere accounts for adaptations. 



Yours very sincerely, 



G. J. EOMAHES. 



May 27, 1889. 



Herewith I return, with many thanks, a pamphlet 

 by Kemer, numbered 738. 



In my experiments with electric spark illumina- 

 tion on plants, I notice that the seedlings, although so 

 wonderfully hehotropic, never form chlorophyll, even 

 if exposed to a continuous stream of sparks for 30 

 hours on end, while they will bend through 90° 

 in seven hours to single sparks following one another 

 at one per second. This proves that there is no con- 

 nection at all between hehotropism and formation of 

 chlorophyll, or vice versa — a point which I cannot 

 find to have been hitherto stated. Do you happen to 

 know if it has been ? If you do not happen to re- 

 member anything bearing on this subject, do not 

 trouble to search or to answer. 



Wallace's book^ strikes me as very able in many 

 parts, though singularly feeble in others — especially 

 the last chapter. He has done but scant justice to 

 Gulick's paper. Had he read it with any care, he 

 might have seen that it fully anticipates his criticism 



' Dartumism, by Alfred Eussell Wallace. 



