1902] BRIEFER ARTICLES 153 
brings to light little of importance. The trichome of the adult leaf 
(fig. 8) is large, heavy, and rough warty; that of the cotyledon is already 
somewhat roughened but is much smaller and less highly tuberculate. 
Erodium cicutarium, on the other hand, shows a definite series of 
structures, all of which are apparently phylogenetically descended 
from one of the number. 
The hair found on the cotyledon of &. cicufarium (fig. 3) is glandu- 
lar, consisting of a round, single celled head, and of two or three stalk 
cells, the walls of which, even under high power, appear perfectly 
smooth. No other modified epidermal structures occur in the coty- 
ledons. The glands upon the petiole are similar, often longer 
stalked. 
i Upon the lamina of an early leaf may be found structures of three 
inds. The first is the gland already described; this, however, is far 
less common here than on the cotyledons. A second is a modifica- 
_ fon of the first by the heavy cutinization and roughening of the basal 
cell (fig. ¢). This type is usually somewhat larger than the earlier 
‘Bland. The third structure is a simple, rough warty, pointed trichome __ 
2 - 5)- On a leaf of this stage the last two mentioned occur in about _ ‘ 
, ina Proportions. On the petiole the long stalked gland of the coty- | 
2 aie Seems to maintain its position, but even here the walls of its os 
: : cular a to show a thickening and more or less of the tabei 
oo leaf, the simple, unicellular, thickened, and tubercu- cs 
a cae  ahiateag an almost continuous covering over the surface. 
addition nee; trichomes are greatly enlarged and elongated. — In : . 
o Sey V6 his form there is present a smaller number of min ute - . 
ag 8a (Ag. 6), short stalked and with heads far inferior in size tothose 
‘Cotyledonar glands, these still maintaining the primitive thin 
- The other forms are almost completely absent. 
Seems to show a variation of the primitive glandular 8 : 
during the phylogeny of the plant. The — 
pend nstrates the peculiar development, out of 2 
a j Structure, of a simple, rough warty. point ; the secon d, the 
intve pana ncoubtedly to be a form intermediate between the 
oe being oe the rough warty point of the adult (ie. 
I | and the ved from the former by the modification of the 
