Ramaley: SEED AND SEEDLING OF WESTERN LARKSPUR. 419 
bock,* mentions that in Delphinium trollifolium and in Del- 
phinium consolida the petioles of the cotyledons are united in 
the same way. 
Anatomy of the Seedling.—As this has apparently not been 
described for any species of Delphinium a somewhat extended 
account will be given. It may be well to state at the outset 
that the present writer has studied only the seedling and not the 
flowering stem. The young root has a thick cortex and small 
central stele. The endodermis, though thin-walled, is con- 
spicuous in properly stained sections because of the thickened 
cuticularized spots on the radial walls. The xylem is arranged 
in two small groups. (See Fig. 7.) In an older portion of 
the root (Fig. 8) the xylem forms an elongated mass in the 
center of the stele. Higher up the vascular tissue extending to 
the cotyledons passes out abruptly on either side at right angles 
to the longer diameter of the xylem mass. (Fig. 9g.) Passing 
upward the xylem strand divides into six or more bundles as 
the transition occurs from root to stem. At the same time. 
the cortex becomes thinner. In a cross section at this point 
(Fig. 10) the cotyledonary sheath is seen surrounding the stem. 
In a section somewhat higher up (Fig. 11) the bases of the early 
foliage-leaves may be seen placed alternately. Here the stem 
abruptly narrows and a rupture of the cotyledonary sheath per- 
mits the emergence of the first foliage-leaf. (Figs. 2 and 3). 
The cotyledonary sheath now becomes smaller, narrowing to 
form the structure previously spoken of as resembling a hypo- 
cotyl. Sections of this structure show that its component 
petioles are not completely fused at any point (Fig. 12.) A 
slit-like passage, lined with epidermis, extends upward to the 
point where the petioles separate completely. 
Anatomy of the cotyledonary Sheath.—No difference is to 
be noted between the outer epidermis and that lining the cavity. 
It is, in both cases, composed of elongated cells which are 
square in cross section. There are two vascular bundles, one 
for each component petiole. These are small but show no pe- 
culiarities in structure. The fundamental tissue is a large- 
celled parenchyma, 
Anatomy of the Lamine of the Cotyledons.—Each lamina 
has three principal veins which send off numerous branches. 
The epidermis is composed of thin-walled cells, somewhat 
* Lubbock. On Seedlings, 2: 96. 1892. 
