HYBRID DROSERA. 943 
rangular area is very averagely intermediate alike in size and shape 
between that of each parent. Numerous hairs, which are structurally 
identical with those of D. filifornus, occupy a like position, but they are 
considerably shorter and show fewer branchings. Across the upper 
transverse boundary a few rather stronger hairs stand out amongst the 
more flattened ones, as an inheritance of the few prominent hairs of D. 
intermedia. The upper epidermal cells are 188-200 «1 x 32, while the 
chloroplasts are very small and scarce. 
The cells of the lower (outer) epidermis are on the average 
186-195 x x 21, and the chloroplasts measure 2°5 ». Numerous two- 
celled sessile glands are inherited from D. filiformis, but the bifid hairs 
characteristic of the other parent are also present, though considerably 
reduced in size. 
It is not the intention to deal in this paper with the details of internal 
leaf anatomy, and accordingly a short comparison may now be made of 
the thre forms, in their petiolar region, between the base and lamina. 
In all, the two-celled glandular or bifid hairs are abundant, and study of 
the figures da, 4b, and 4c on fig. 105 will graphically illustrate their 
relative size. In D. filiformis they are only slightly elevated above the 
epidermis on subjacent cells, and they measure 28 ~x18 pp. In D. 
hybrida they are saccular elevations above the epidermis, and measure 
33 p high by 32, across. In D. intermedia the hairs are bifid bladder- 
like appendages, each 45-50 , high by 87 » across. 
Stomata are now present over the under surface of the three and 
show noteworthy differences. Those of D. filiformis are 38 « 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 (fig. 105, No. 6a). The chloroplasts of the guard 
cells are 20-22 in number, and measure 3°2 » across. In the hybrid the 
stomata are on the average 32 4 x25», and show a very slight tendency 
toward inequality of size or position (No. 6b). The chloroplasts are 
15-17 in number and measure 2°5 » across. In D. intermedia the 
stomata measure 26 u x25; the guard cells are very neatly crescentic 
and fitted at their ends (No. 6c). The chloroplasts are 12-14 in 
number and measure 1°8, across. 
The blade of the leaf is tentacular throughout on its upper surface. 
The general colour of the lamina cf the three forms is markedly different. 
Leaves of D. filiformis might be described as pinkish-green, those of D. 
intermedia as deep crimson green, while those of the hybrid are averagely 
intermediate to the naked eye. Microscopically examined, these differ- 
ences 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 colour 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 distributed 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 
rk 2 
