1915] CHRYSLER—RAYS OF CEDRUS 389 
rence of the marginal cells, but the mixture of tracheids and 
parenchyma cells constituting the marginal row. The parenchyma 
of the marginal rows, like that of the central rows, is more or less 
completely filled with starch grains, which have been omitted from 
the figures for the sake of clearness. In some instances the mar- 
ginal cells are practically restricted to the region of the end of an 
annual ring, and in such cases the marginal cells are entirely of a 
parenchymatous nature, as is shown in fig. 3, which is taken from 
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Fic. 2.—C. deodar, stem; a continuation of fig. 1, as may be seen from the presence 
of a shadowy cell on the lower margin of the ray in both figures; X 290. 
hear the cambial region of a root of C. libani. In this and other 
figures is to be seen the unusual shape of the marginal cells, which 
are triangular or pointed or tailed. It will be recalled that in 
most genera which possess marginal cells these are rectangular 
cells elongated in the radial direction, as are the central cells 
of a ray. 
The lower margin of the ray shown in fig. 2 contains one of the 
Shadowy cells or “ghosts” referred to by THompson (7, 8) as 
characteristic of Abies, and considered by him to represent an 
