6 4 Newcombe. — Cellulose- Enzymes. 
Lupinus albus, it does not occur in all cases. That the four 
or five peripheral rows of cells of the cotyledons become 
thin-walled is true ; but since these cells during germination 
increase considerably in size, one cannot be certain that all 
the material of the thick wall is not consumed in building 
the more extensive thin wall. As in the action of enzymes 
on the walls of cells in sections, so in normal germination, 
the membranes become hyaline, and the progress of this 
hyaline zone from the cell-cavity toward the middle lamella 
gives at first sight the impression that the wall is narrowing 
down, since the hyaline part is wellnigh invisible. This is 
probably the explanation of what I believe to be an error 
of fact in Tschirch’s Angewandte Pflanzenanatomie. How 
then are Nadelmann’s results to be regarded ? The possibility 
has already been indicated of a difference in behaviour in dif- 
ferent individuals of the same species. In a set of individuals 
of the same age, I have found in some withering cotyledons 
the thin-walled condition of the peripheral cells extending 
two or three rows deeper, and the thick walls of the interior 
cells looking much poorer in substance, than in other coty- 
ledons of the same stage of development. I feel certain that 
when the cotyledons wither and die they are not all in the 
same stage of exhaustion. In this connexion it may be well 
to recall the various methods of solution of reserve cellulose 
in germination of seeds, as classified by Reiss 1 . 
Therefore, though I have not found corrosion and final 
disappearance of the cell-wall in germination, I am not 
disposed to assert that it never takes place in this plant, 
especially since I have seen the complete wall dissolve in 
sections immersed in an enzyme-solution. A word must be 
spoken, however, as to a possible source of error in Nadel- 
mann’s conclusions : — the pits in the walls of the cotyledonary 
cells of Lupinus albus look, when the walls are hyaline, quite 
like clefts and corrosion figures. Moreover, in cases of 
exhausted cotyledons ready to fall, I have several times 
1 Ueber die Natur der Reservecellulose, & c. : Ber. d. d. bot. Gesellscb., vii 
(1889), 322. 
