270 Rhodora [NOVEMBER 
This style of tentacle prevails throughout the genus. On the youth- 
ful leaves of all the species which I have been able to see in their 
early stages there are, however, two kinds of tentacles. ‘Those on 
the margin of the leaf are more complex in this respect, that the 
gland is borne laterally upon the expanded extremity of the tentacle 
(Fig. 1). The axis of the gland is at right angles to that of the 
stalk. 
The flattened, round, ovate, or elliptical extremity, serving as a 
support for the nearly hemispherical gland, extends on all sides 
beyond the base of the latter. Tentacles possessing such a structure 
are found on young individuals of, not only Drosera intermedia, but 
also D. rotundifolia, capillaris, and binata, and sometimes on //Zfor- 
mis. In the first three species named they persist nearly or quite to 
the maturity of the plant, but under a much changed aspect. In 
Drosera intermedia they disappear when the leaves become spatu- 
late, if not before. In Drosera rotundifolia they may or may not be 
present in the modified form throughout life, while in Drosera capii- 
laris, according to my material, they disappear. In several of the 
exotic orbicular-leaved species they are found in the adult, as I dis- 
cover from herbarium specimens. In Drosera binata they begin to. 
disappear as soon as the leaves depart from the primitive orbicular 
pattern, and are not found even in a modified form in the adult. 
They must be regarded as reversionary when they appear on leaves 
of primitive type in the species destitute of such tentacles at maturity, 
and also when they appear in those species which at maturity possess 
them only in a modified form. In Drosera intermedia they seem to 
me clearly to be products of reversion, and to constitute valuable 
indices for the study of the laws of reversion. 
My experimental plants bore them seemingly as the direct result 
of the weakening to which I subjected them. The mode of their 
appearance was interesting. ‘They appeared first at the tip of the 
leaf. Perhaps the first leaf to manifest the reversion would have 
but one tentacle of the flat-headed style, and in that case the very 
end tentacle would be the aberrant one. The next leaf would have 
perhaps three or four, at the end, affected. The atavistic tendency 
would then pass down the margin toward the base in succeeding 
leaves, until all the marginal tentacles had become reversionary, 
except one or two next to the petiole. 
The effect recorded, namely the reappearance of ancestral traits 
