Between Drosera filiformis and D. intermedia. I 
9 
three and show noteworthy differences. Those of D. filiformis 
are 38 uw long by 24 » wide, and one guard cell is usually 
larger than, or somewhat obliquely placed to, the other, while 
a more or less evident sinus exists at their opposed ends 
(Plate XII, Fig. 62). The chloroplasts of the guard cells are 
20-22 in number, and measure 3.2 wacross. In the hybrid 
the stomata are on the average 32 w X 25 w, and show a very 
slight tendency toward inequality of size or position. (Fig. 
62). The chloroplasts are 15-17 in number and measure 2.5 
pacross. In D. intermedia the stomata measure 26 uw X 25 4; 
the guard cells are very neatly crescentic and fitted at their 
ends (Fig. 6c). The chloroplasts are 12-14 in number and 
measure 1.8 y across. 
The blade of the leafis tentacular throughout onits upper sur- 
face. The general color of the lamina of the three forms is mark- 
edly different. Leaves of D. filiformis might be described as’ 
pinkish-green, those of D. zxtermedia as deep crimson green, 
while those of the hybrid are averagely intermediate to the 
naked eye. Microscopically examined, these differences are 
found to be due to the relative distribution of a rich crimson- 
red pigment, which is only present in the tentacular hairs. In — 
D. filiformis it is wholly confined to the oval or elliptic head 
of each hair, there being a sharp contrast in color between the 
green top of the hair-stalk and the red base of the head. In 
D. intermedia the pigment is richest in the head, but is dis- 
tributed in the cells of each hair throughout two-thirds of its 
length. In the hybrid the. pigment is less rich than in the 
last, and extends throughout one-third to rarely one-half the 
length of the stalk. 
The tentacular hairs of all three vary greatly in length, so 
that no exact comparison is possible. The club-shaped head 
of each in D. filiformis is broadly elliptic and is on the average 
220 X 165 w. The head of each hair in D. intermedia is ovate- 
truncate and measures 230 X 105 yw. That of the hybrid is 
elliptic-ovate in outline and measures 210 X 125 4. 
