Conditions influencing regeneration of hypocotyl. 
By 
Prof. George P. Burns 
and 
Mary E. Hedden. 
(With 4 images in tlie text.) 
It lias long been known that tlie hypocotyls of many seed- 
lings will produce, ander some conditions, one or more 7 ,adventi- 
tions u sboots. 1 ) 
The writers cited, worked witk nninjured seedlings and 
establisked tke following facts. 
First, that rnany seedlings produce „adventitious“ buds 
normally. Ir misch points out that ab out 50 % of tke seedlings 
Anagallis arvensis do this. 
Sec ond, that many seedlings produce these buds only 
under exceptional conditions. Wydler found that only those 
seedlings whicli he kept in crocks produced hypocotyl buds, 
those in the open never doing so. Braun found the sarne and 
agreed with Irmisch and others, that an abundance of water 
migkt be the causal factor. 
l ) Böper, Ennmeratio Enphorbiarnm. 1824. 
Bernliardi, Linnaea YII. 1832. p. 572. 
Cliavannes, Monographie des Antirrhinnm. 1833. 
AYydler, Bot. Ztg. 1850. Er. 22. Elora. 1856. Er. 3. 
Berner Mitteil. Er. 485—487. 
Irmisch. Über die Keimung und die Erneuerangsweise von Convol- 
vulus sepium und C. arvensis , sowie über hypokotylisclie Adventivknospen 
bei krautartigen phanerogamen Pflanzen. (Bot. Ztg. Bd. XY. 1857. p. 433. 
Elora. 1853. p. 522. Elora. 1857. p. 439.) 
Braun. Adventivknospenbildung am ersten (hypokotylen) Stengel¬ 
glied. (Sitzungsber. der Eaturf.-G-es.. Berlin. 1870: vergl. auch Bot. Ztg. 
Bd. XXYIII. 1870. p. 438.) 
Zabel, Entwicklung der von der Achse abgetrennten Keimblätter. 
(Bot. Jahresber. Bd. X. 1882. p. 32.) 
Beyer in ck, Over regeneratieverschynselm aan gespleten Vegetation 
punten van stengelsen over bekervornung. (Bot. Centralbl. 1883. p. 231.) 
Beobachtung und Betrachtungen über Wurzelknospen und Eebenwurzeln. 
Amsterdam 1886. 
