386 Bur ns and He d den. Conditions infLu encing regeneration of lrypocotyl. 
seemed capable of forming a bnd, the hypocotyl in some cases 
was almost completely covered with bnds from base to apex. 
The bnds were developed near tlie base of the hypocotyl 
in Linaria , bnt in Antirrhinum and Linum thev were more 
generally distributed. 
As a rule the hypocotyl of Antirrhinum and Linum became 
bent sometimes as much as 90° and the bnds then tended to 
crowd on the upper side, very few if any were produced on the 
nnder side. These bnds either developed one after the other or 
several at a time, bnt no very definite arrangement was ever 
determined. In the majority of cases, however, the second bnd 
developed below the first. 
In several cases the hypocotyl bnds were ent off as soon 
as they formed, and in this way an almost indefinite nnmbcr 
conld be forced to develop. They were produced either above 
or below the origin of the first bnds; there was no fixed rnle. 
Seldom more than two of the bnds developed into shoots. 
generally one, bnt if they were ent off some of the nndeveloped 
bnds took their places, or a new shoot was formed on the stern 
of the old one. As soon as the hypocotyl shoots began to 
develop they grew very rapidly and took tlie place of the main 
axis, which became bent over to one side. After a week or two 
the nndeveloped bnds died, the shoots evidently growing at 
their expense. The hypocotyl bnds when produced on nninjnred 
plants of Linaria , as observed by Bernhardi, became the flower 
stalk and the main stem soon died. One other fact shonld be 
mentioned in this connection. Often the seed coats cling to the 
cotyledons and do not allow them to open. They are not then 
exposed to the light and cannot serve as assimilating organs. 
In snch cases tlie hypocotyl produced bnds as if it had been 
wonnded. This was tested fnrther by covering the cotyledons 
with plaster of paris. In this case regeneration took place. It 
is thns evident that not the wonnd 1 ) bnt the absence of the 
normally present fnnctioning cotyledons give the first stimnlns. 
The length of time reqnired for the prodnetion of snch .,ad- 
ventitions“ bnds differs, widely depending as we will see to 
some extent npon external conditions. This is not entirelv 
trne. In jSTovember a large nnmber of seedlings were decapita- 
ted and kept in the greenhonse. The first bnds appeared only 
after 37 days. The same experiments condncted in Jannary 
later gave resifits in one third of that time. 
A n i s o p h y 11 y. The phenomenon 2 ) varies witli different 
individuals bnt not with changing external conditions as far as 
learned. 
Linaria bipartita splendida develops only a few bnds when 
the cotyledons are removed. Out of 1-10 individnals, 2 developed 
1 ) Goebei, Uber Regeneration im Pflanzenreicli. (Biolog. Centralblatt. 
Bd. XXII.) 1902. AYeitere Studien über Regeneration. (Flora. 1903. p. 132.) 
2 ) Küster, 1. c. 
