IN VEGETABLE BIOLOGY. 365 
do not perceptibly apostrophize, even long after those of the 
mesophyll have done so. Clematis florida, tCircea Lutetiana, 
*Bellis perennis, Achillea Millefolium, Chrysanthemum Matri- 
caria, t Helianthus annuus, OLactuca sativa, 0 Anagallis arvensis, 
tMercurialis annua, and others may be adduced in support of 
this statement, not the least trace of apostrophe having shown 
itself in their epidermis after three days’ darkness. The chloro- 
phyll, however, sometimes appears to slowly shift its position. In 
the previous memoir I described massing of the epidermal grains 
of Pteris serrulata after three weeks in the dark, and’ confine- 
ment for a week caused in the epidermis of Hydrocharis Morsus- 
vane massing in an angle of the cell or on the free (superficial) 
wall: moreover, in some cases nuclear massing was observed. 
But Stóhr! states that the natural position of epidermal chloro- 
phyll is either upon a front wall or in the immediate neighbour- 
' hood of the nucleus ; and I am inclined to support him, believing 
that the nuclear massing in these cells is not an effect of light or 
its absence, or at most is but obscurely related thereto, seeing 
that not only may it be seen in dark-loving plants, but under any 
conditions of illumination as well. 
There is therefore no alternative but the conclusion that if 
apostrophe (negative or positive) be manifested in epidermal cells, 
it is exceedingly rare. Could a stronger argument be adduced 
against the doctrine that the chloroplasts contribute to these 
movements? It might indeed be urged that epidermal chloro- 
phyll is in some respects different from that of the underlying 
cells, since Stéhr? declares that starch cannot be detected in it. 
This, however, traverses De Bary's? statement that epidermal 
chloroplasts “ eventually " contain starch. Ihave endeavoured‘ 
to show both these views to be incorrect ; for not only are there 
many species (42 per cent. of those examined) with starchless 
epidermal chlorophyll throughout life ; but the grains of species 
with vigorously assimilating chlorophyll’ can readily be dis- 
amidated in darkness and recharged with starch in light. Now 
the two lists just given include the names of species (i.) with 
* Sitzb. derk. k. Akad. Wien, 1879. ? Op. cit. 
* Vergl. Anat. p. 70. English Edition, p. 66. 
* Journ. of Bot., Dec. 1887. . 
* I speak in the conventional sense, without auy special reference to Prings- 
heim's theory. 
