34 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



Stems by cultivation of plants in chambers of low humidity, exter- 

 nally resembling those resulting from etiolation. No anatomical com- 

 parisons were made, however. 



By the recent researches of Nabowick '"^ etiolated seedlings of 

 maize, sunflower and onion were found capable of anaerobic growth, 

 although further evidence upon the matter is needed. 



Neljubow '^^ describes the horizontal positions assumed by stems of 

 Pistim and other plants in darkness and ascribes these positions to 

 the influence of various external forces, the relations of which are 

 not made clear. 



Undoubted instances of growth which is accelerated or facilitated 

 by light are given by Schulz^"^ as the result of observations on spores 

 of mosses, ferns and equisetums. Germination of these bodies are 

 said to occur only in light with the exception of those of Ceratopteris 

 thalictroidcs and the Ophioglossaceae. In some instances the stimu- 

 lating action of the rays is necessary to start growth, while in others, 

 growth must wait on the construction of material by the chorophyl 

 apparatus before new cells of protoplasm may be built up. It was 

 found possible to replace the stimulating influence of light by that 

 of other forces in a few instances. 



These results are in accord with those attained by Borodin ^^* thirty- 

 four years earlier. Borodin tested the spores of Aspidnim spinu- 

 losum foenisecci\ Aneimia Phyllitidcs longifolia, Allosoi-tis sagittattis, 

 Aspjdium molle^ Polypodmni repens, Phegopteris effusa^ Asplenium 

 alattim, Asplcniimi lasiopteris and another species of Asplenium and 

 found that light was an indispensable condition of germination of 

 these forms, the least refrangible rays being active in the matter, 

 the blue rays having the same effect as darkness. Milde ^-^ had 

 previously reported that spores of Eqiiisettim would germinate in 

 darkness although this result has not been confirmed. 



No attempt has been made in the foregoing sketch to review the 

 literature of influence of light upon germination of seeds. It is well 



'^^ Nabowick, A. Wie die Fahigkeit der Hoheren Pflanzen zum anaeroben Wach- 

 stum zu beweisen und zu demonstriren ist. Ber. d. deut. Bot. Ges. 19: 222. 1901. 



'^^ Neljubow, D. Ueber die horizontale nutation der Stengel von Pisum sativum 

 und einiger anderen Pflanzen. Beih. Bot. Centralb. 10: 128. 1901. 



^^'^ Schulz, N. Ueber die Einwirkung des Lichtes auf die Keimungsfjihigkeit der 

 Sporen der Moose, Fame, und Schachtelhalme. Beih. Bot. Centralb. n : Si. 1901. 



'2* Borodin, J. Ueber die Wirkung des Lichtes auf einige hohere Krvptogamen. 

 Mel. Biol. 6: 1529. 1867. 



'^* Milde. Zur Entwickelungsgeschichte der Equiseten und Rhizocarpen. Nova 

 Acta Acad. L. C. 23 : 2. 



