68 New combe. — Cellulose-Enzymes. 
ferment does not exist there, but that the endosperm-walls 
are dissolved by contact with the cotyledon in whose cells 
the enzyme exists. While, as is well known, the endosperm- 
walls do not become softened in germination except within 
about t mm. of the cotyledon, yet that they do soften and 
begin solution, as Reiss 1 has shown, at this distance from 
the cotyledon, indicates that the enzyme travels from the 
cotyledon out into the endosperm ; and therefore a cell-wall- 
ferment may be expected in an extract of the endosperm. 
Since the method of removing the cotyledons from the 
endosperm, described in the preceding pages, may have 
allowed some of the enzyme from the cotyledons to be 
carried over to the endosperm, and thus vitiate the result 
possibly to be obtained with endosperm-extract, a more 
careful means was employed by which the endosperms re- 
ceived no juice from ruptured cells of the cotyledons when 
the latter were removed. In the first place the seedlings 
were allowed to grow till the remaining shell of endosperm 
was reduced to a thickness of i mm. to 2 mm., the leaf, as it 
appeared above ground, being cut back in order to compel 
the plant to draw all its food from the endosperm. The 
seedlings were then taken from the garden, the petiole of 
the cotyledon cut off close to the endosperm. Next, the 
endosperms were thoroughly cleaned with brush and water 
and the superficial water allowed to dry off. With a scalpel 
a slit was made along the endosperm just opposite the 
groove, when it was found that by a little effort with fore- 
fingers and thumbs the endosperm shell could be split into 
longitudinal halves, leaving the cotyledon intact. In not 
more than three or four out of seventy-two individuals, was 
the cotyledon cut into by the knife, or torn when breaking 
the endosperm apart. Thus it was certain that all the extract 
obtained from the endosperm, was normally present in the 
endosperm. It seems probable also that all the extract was 
contained in the softened layer of endosperm lying against 
1 Ueber die Natur der Reservecellulose und iiber ihre Auflosungsweise bei der 
Keimung der Samen : Ber. d. d. bot. Gesellsch., vii (1889), 322. 
