SS Sei 3 = i iat 
1906] SHREVE—SARRACENIA PURPUREA I19g 
side of the leaf rudiment which faces the growing-point, giving rise 
to a pit which is destined to become the cavity of the pitchered leaf 
(jig. 52). The basal part of the 0-shaped outgrowth now begins 
to grow upward, in which it is accompanied at the same rate by the 
upper portion of the 0, which at the same time carries forward the 
apical growth of the leaf (fig. 53). The cavity of the pitcher thus 
grows in depth by the upward growth of the tissue by which it is 
surrounded, The bottom of the cavity is subsequently elevated 
to some extent by the further growth of the tissue beneath it, but 
there is no sinking of the bottom of the cavity, considered as a possi- 
bility by ZrppeRER.? The entire carly development of the leaf 
resembles closely that which has been described for Darlingtonia 
californica by GOEBEL.3 
The first epicotyledonary leaf reaches its maximum size at a 
length of about 2.5°™, and is slender in form, the cavity reaching 
well down toward its base, and the wing being but slightly developed. 
At the summit it is hooded in such a manner as to resemble the 
mature leaf of S. variolaris. The walls of the pitchers of the seedling 
are six to eight cells in thickness, with open mesophyll, chlorophyll in 
all the cells, and stomata over the entire external epidermis. There 
are two principal strands of vascular tissue, one in the base of the 
wing and one on the opposite side of the pitcher, with smaller anas- 
tomosing strands between these. In the throat, of the pitcher all 
the epidermal cells are produced into long projecting points; lower 
in the pitcher occasional epidermal cells, smaller than the others, 
give rise to long heavy-walled hairs, while in the bottom of the 
pitcher the epidermal and first layer of subepidermal cells are small 
and heavy-walled. 
While each leaf of the young plant is passing through its period 
of most active growth, the internode between it and the next lower 
leaf is also elongating rapidly. A young leaf appears for this reason 
to arise from the petiole of the leaf below it (fig. 5z). The relative 
elongation of the internodes is far greater in the seedling than in the 
adult plant. 
The growth of a single plant from seedling to adult was not fol- 
Beitrag zur Kenntniss der Sarraceniacees: Inaug. Diss. Erlangen. 1885. 
3 Pflanzenbiologische Schilderungen II. 5:73-02- pls. 19-29. 1893- 
