THE AMERICAN MIDLAND NATURALIST 79 
the upper one bearing two young plants one some distance from the 
other at the distal extremity; the lower one, in which decay took 
place at the extremity next to the parent, bears but one plant. 
Study of Lophion striatum (Viola striata Ait.) seems to indicate that 
this process of vegetative propagation takes place also from its 
roots though no experiments were made to determine this beyond 
doubt. Subsequent observations of yellow violets in the field show 
that vegetative multiplication is very common in the members of 
the Crocion group. 
THE ANATOMY OF THE SEEDLING. 
THE PrimARY Root. (Figs. 6-7). 
In’ cross section the single vascular bundle (stele, central 
cylinder) of the primary root (Fig. 6-7) is well marked being of 
the radial type with leptome (phloem) on either side of the hadrome 
(xylem). The hadrome arrangement is diarch exarch; that is, 
the initial hadrome vessels (protohadrome, protoxylem) are found 
externally to the subsequent hadrome vessels (metahadrome, 
metaxylem) which are formed centripetally. The first hadrome 
vessels developed are of the spiral and annular type of small lumen 
with the former in the majority. The tracheae of the metahadrome 
though larger in caliber possess the same markings that the initial 
tracheae. The vascular bundle is limited externally by a single 
layer of cells, forming a continuous membrane, the pericycle. 
This is homogeneous, formed of thin-walled flattened parenchy- 
matous cells which are bounded externally by the endodermis 
which encloses the stele. 
There is soon developed from the embryonal meristematic 
tissue the procambium a region of actively dividing cells the 
secondary meristem or cambium found between the protohadrome 
and protoleptome giving rise subsequently to secondary hadrome 
on the inner side and secondary leptome on the outer side. 
The extrastelar fundamental tissue (periblem, primary cortex) 
is limited internally by the endodermis inclusively and externally 
by the epidermis exclusively. The endodermis is composed of a 
single layer of cells which show in cross section suberization along 
their lateral walls. The endodermis in vertical section is differenti- 
ated from the cells within by elongation in the vertical direction 
and are somewhat narrower than the cells immediately exterior, 
