ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
558 
eonids on tlie promycele has ceased, develope haustoria on the solid 
substratum, and then the organs of fructification ( StropJiaria pileus) on 
special branches. The Oospora eonids which germinate on straw in dung- 
hills also produce fresh eonids and a mycele with agaric-fructification. 
Red Pigment of Amanita muscaria.* * * § — Dr. A. B. Griffiths has 
extracted the colouring matters of this fungus ; he assigns to it the 
formula C 19 H 18 0 6 , and proposes to call it amanitin. It is insoluble in 
water, soluble in chloroform and ether. Its solutions give no charac- 
teristic absorption hands in the spectroscope. 
Coprinus.f — Mr. G. Massee gives a monograph of all the known 
species of this genus of Fungi, 169 in number, arranged in six sections, 
and including a few new species, one of which, Coprinus gigasporus , has 
the largest spores of any known agaric. The only invariable special 
characteristic of the genus is the deliquescence of the gills at maturity; 
and the author regards this, with other characters, as indicating a 
survival of the primitive group of Fungi, from which the entire modern 
group of Agaricinem has descended. 
Cyclomyces.f — M. N. Patouillard gives a monograph of this genus 
of Polyporese. To the five species hitherto* recognised he adds others 
previously included under ether genera. Instead of retaining the inde- 
pendence of the genus, the author prefers that it should he sunk in 
Polystictus. 
Protophyta. 
a. Schizophyceae. 
Recent Advances in the Determination of Diatom Structure.! — 
Mr. C. F. Cox directs attention to a mode of interpreting observations 
of diatom structure which, according to him, reconciles many divergent 
views on this subject. The use of modern high-power objectives of wide 
angle enables us to separate visually planes w hich were formerly merged 
in one another. In this way the diatom-valve is found to possess a 
“ complex structure the nature of which must he deduced from various 
appearances at different focal levels.” The so-called “ black dot ” and 
the “ white dot ” resolution may thus he correct for different focal planes. 
The author does not agree with the view that the valve has a lami- 
nated structure. He considers that the alveolar structure is “ the one 
invariable and characteristic matter w r e have to do with” in both the 
finer genera of diatoms and also in the coarser discoid forms. 
In a series of diagrams an attempt is made to represent the essential 
points in the structure of the diatom-valve. In these the oval alveoles 
are shown with the connecting cell-walls, but while in one diagram the 
surface-line is represented as straight, in another it is undulating, 
owing to the projection of the caps of the alveoles, and in another by 
the projection of the cell-walls. In the last case, in focusing upon the 
summits of the thickened and projecting cell-walls, “black dot” is 
the correct resolution, but in focusing down lou'er upon the crests of 
the alveoles, “ black dot ” will change to “ white dot.” These diagrams 
* Comptes Rendus, exxii. (1896) p. 1342. 
f Ann. Bot., x. (1896) pp. 123-84: (2 pis.). 
t Bull. Soc. Myc. France, 1896, p. 45. See Hedwigia, xxxv. (1896) Rep., p. 80. 
§ Journ. New York Micr. Soc., xii. (1896) pp. 57-69. 
1896 2 q 
