RESERVE CELLULOSE. 13 



1. That reserve cellulose is not identical with pure cellulose. 



2. That it probably consists of a ground substance of identical chemical nature 

 in all the seeds; Paris and Trillium may be excejjtions. 



3. That the slight differences, noticed in the behavior of reserve cellulose, are 

 due to the association of other substances with this ground substance in the same wall. 



Reserve Cellulose during Germinatiox. 



In order to study the history and final fate of reserve cellulose, seeds were planted 

 and examined during the various phases of germination, until the young plants no 

 longer depended upon the seed for nourishment. 



Sachs', as early as 1862, showed that reserve cellulose is a true reserve material, 

 and is used up during the processes of germination. The seeds he studied were 

 Allium cepa and Phoenix dacfylifera. Reiss- has jiroved the same to be true of the 

 reserve cellulose of many other seeds, both dicotyledons and monocotyledons; and he 

 has given particular attention to the mechanical process of solution. Furtheiinore, 

 he has proved, macrochemically, that many seeds containing reserve cellulose, among 

 them Iris i^seudacorus and Allium, cepa, yield mannose by hydrolysis. 



It is of interest to follow under the microscope, so far as the limited development 

 of microchemistry will allow, the chemical result of solution. 



The following sketches of the history of the germination of the seeds of Polygo- 

 natum multljiorum., Iris pseudacorus, etc., will illustrate the changes of the reserve 

 cellulose during solution and absorption. 



Germination of Seeds of Polygonatum, m,idtiJiorum. 



Seeds of Polygonatum 7mdtijiorum, gathered Sept. 11, 1892, were planted April 

 24, 1894, after three days' soaking in water. 



After eight weeks, on June 19, they were found to have sprouted. The manner 

 of germination is peculiar. The first effort of the plant is to establish itself finnly 

 in the soil, and, to this end, it begins at once the construction of the rhizome 

 which is so characteristic of the "enus. 



o 



The seed is spherical and hard, containing a large endosperm consisting of 

 good-sized cells, whose walls are considerably thickened with reserve cellulose. In 

 the cells are present oil and reserve protein matters, but no sugar and no starch. 

 (Plate 1, fig. 1, illustrates these cells.) The embryo is small (PI. 3, fig. 1), and 



' Sach.s, Keimungsgeschichte dfi' Allium cepa. etc. Bot. -Reis.s, Reservecellulo.se, Laiidw. jalirbiiolier, 18, .s. 71 1 . 



zeit., 1862-60. 



