NOTES AND MEMORANDA. 
157 
Janczewski and Rostafinski Lad been too hasty in their criticisms. 
Areschoug mentions that Wittrock has found zygospores in Hcema- 
tococcus lacustris ( Protococcus nivalis), the existence of which Rosta- 
finski denied. 
The Effect of Frost on Chlorophyll Granules. — Herr Haberlandt 
states that the granules, except in evergreens, undergo changes at 
4° to 6° C. The granules thus affected contain cavities (vacuoles), 
become rent on the outside, and aggregate into larger or smaller 
masses. The granules which contain starch are more easily destroyed 
by frost than those which contain none. The chlorophyll in the 
palisade tissue (the denser parenchyma) is more easily injured than 
that in the spongy tissue, and the latter than that in the guardian 
cells of the stomata. 
Structure of the Testa in Cucurbitacece. — The ‘ Journal of Botany ’ 
gives an abstract of a recent paper on this object in the ‘ Botanische 
Zeitung’ (December, 1876) by Herr Dr. Fickel. After fertilization 
of the ovule, the outer (epidermal) layer of cells of the outer integu- 
ment undergoes division, and gives origin to two underlying cell- 
zones. In the full-grown seed of most genera the epidermal cells of 
the testa are provided with bands of thickening, which either extend 
wholly or partially across the cell, and are then either simple or 
branched, or else run up and down the cell-wall, the opposite thicken- 
ings being sometimes connected by cross-bands. The cell-zone 
immediately below the epidermis consists either of one layer or several 
layers, which, in the latter case, are more numerous at the margins of 
the seed than elsewhere. The succeeding zone is generally several- 
layered, and the cells being usually very thick-walled, it takes in 
most instances the principal share both in protection of the embryo 
and in the due adjustment of the supply of water during germination. 
The layers of cells lying under this zone and produced from the outer 
integument, as well as all those derived from the inner integument, 
remain thin-walled and are pressed together by the growing embryo. 
NOTES AND MEMORANDA. 
Beck’s Vertical Illuminator and Wenham’s Reflex Illuminator 
in Professor J. E. Smith’s (U.S.A.) Hands.— The ‘ Cincinnati Medical 
News ’ ( J une) contains a paper descriptive of Professor Smith’s 
modification of both of these instruments, with the most startling 
results appended. However, as the improver not only does not state 
the nature of the modification he has made nor the results of his 
observations, we are not justified in giving his remarks at any length. 
Moreover, we must beg of Professor Smith to be a little more cautious 
in his expression of results. It is not satisfactory to anyone who 
is at all familiar with modern microscopic research to read either of 
