1897 } CURRENT LITERATURE 67 
Whichever pair is used, the treatment is essentially the same. The wood 
is to be painted first with solution I, which is allowed to become just dry ; 
then solution II is applied and allowed to dry in. The process is then 
repeated. A third application may be necessary to obtain the complete 
blackening desired. The surface should then be washed with lukewarm 
water to remove any superfluous salts. After drying, the surface may be 
finished in oil as untreated wood. When complete it should be a smooth 
dead black with only the polish due to rubbing.—C. R. B 
IN THE Botanisches Centralblatt 69 : 277, 1897, is found an abstract of a 
Russian paper by Chmilewskij, without citation as to its place of publication, 
giving an account of researches on the structure and multiplication of pyre- 
noids in algz which is worthy of notice. Chmilewskij studied particularly the 
large pyrenoids of Zygnema. Contrary to Schmitz, he finds, by an examination 
of sections of the pyrenoid, that the granules of the starch jacket are not separ- 
ated by chromatophoric substance from the pyrenoid, but that they lie directly 
against it, fine plates of pyrenoid substance extending out between them, so 
that the pyrenoid is stellate. In spite of the smallness of the pyrenoids in 
several other alge (Spirogyra, Cladophora, GEdogonium, and many Protococ- 
caceze) he was able to establish the same structure. In Zygnema he ascer- 
tained, by a study of living as well as of fixed material, that division of the 
cell generally precedes that of the chromatophores and pyrenoids, each 
daughter cell having at first a single chromatophore and pyrenoid, which 
later undergo direct division. In Spirogyra about dusk, and before the 
nocturnal cell division, the pyrenoids divide, each forming two or some- 
times three or four, often of unequal size. Following this occurs the split-, 
ting of the plasma filaments which radiate from the nuclear region and are 
attached to the peripheral plasma beneath the pyrenoids. This is the reverse 
of the statement of Strasburger, who states that the pyrenoids are formed 
where the filaments are attached. In different species of Spirogyra the 
author determined that in the zygotes the pyrenoids of the female cell per- 
sist and can be recognized at any time. No ground for belief in the forma- 
tion of pyrenoids de novo was found. Researches on other alge are in 
progress.— C. R. B. 
RECENT BULLETINS from the experiment stations of interest to botanists 
are as follows: H. H. Lamson (N. H. no. 45, pp. 45-56) gives results of use 
ot Bordeaux mixture for apple scab and potato blight, and of corrosive sub- 
limate for potato scab. B. D. Halsted (N. J. no. 120, pp. 3-19) has con- 
tinued his trials of fungicides for potato scab and for soil rot of sweet pot- 
atoes and finds sulphur superior for both. He presents considerable original 
data. J. C. Arthur (Ind. no. 65, pp. 19-36) reports the successful use of 
formalin for potato scab. He also gives a method for careful percentage 
determination of the injury in a crop from scab. S. A. Beach (N. Y. no. 117, 
