1894. ] Anatomical and Physiological Researches. 67 
The secondary mestome bundles, which have originated 
from the secondary parenchyma, serve naturally as carriers 
of such substances as are useful to the plant. This is very 
conspicuous in Déoscorea, where starch grains form heavy 
masses around the mestome bundles; this starch becomes 
transformed, however, upon the renewed growth in the spring. 
At this time it takes a reddish-violet color with iodine, and 
the grains near the mestome bundles have decreased in size 
and look as if they were partly digested. THEO. HOLM. 
The role of the pericycle in the root of Draczna marginata.?* 
_The roots in certain monocotyledons show an increase in 
diameter, a fact that has been observed in Aletris Jragrans, 
and in some species of Dracena, e. g., D. marginata, D. re- 
differentiated into a corresponding number of secondary mes- 
The central cylinder, therefore, is the struc- 
cases, n marginata by Morot.* The pericycle had in these 
few A aaa preserved a certain activity, showing a 
Ons of its cells, 
seg song gh observations have been made by the author, 
nata Allt led the structure of the roots of Dracena mar gt- 
spcagi the roots showed the presence of secondary forma- 
: The pericycle had to a certain ex- 
tion, not pr itiplied, and had here a true mechanical func- 
these SMG eviously noticed. A transverse section of one of 
ts, in which . . 
formations, sh there is not yet any sign of secondary 
Ge Stdodermis, the cell walls of which are 
‘ 0: 
De Corp 
Bul EMOY, Du rdle d : . ase. 
all. dela soc. bot. de Vitis aor Soe la racine du Dracena marginata 
1s 3. 
217, ; Moror, Recherches sur le péricycle. Ann. d. sc. nat. Bot VI. 20: 
