Thar? ee eee, 
1909] CURRENT LITERATURE 237 
of two parts, a central portion and the surrounding zone. The pyrenoid is 
influenced by its environment, and easily becomes swollen and dissolved, leaving - 
vacuoles in its place. Such a compound structure of the pyrenoid is shown only 
in the stained preparation, and when it is not differentiated with stains the pyrenoid 
appears quite homogeneous. ScHuitz’s description of the pyrenoid as a homo- 
geneous body may perhaps be based upon the unstained material—Snicto 
YAMANOUCHI. 
Karyokinesis in Oedogonium.—Since STRASBURGER’S and KLEBAHN’s work 
on Oedogonium, there had been little published on mitosis in this form until 
WISSELINGH’S paper appeared. STRASBURGER’s material was O. tumidulum Kg., 
EBAHN’S O. Boscii Witte, and WissELINGH’s material was O. cyathigerum 
Witte, fixed in Flemming’s solution. After being left in the solution for one 
day, it was treated with 20 per cent. chromic acid. By the action of the Flem- 
ming solution and the chromic acid solution, the cell wall and cell ¢ontents 
become entirely dissolved, and the nuclear membrane is also dissolved by the 
action of 20 per cent. chromic acid ‘solution. The chromosomes during mitosis 
were studied in their isolated condition. 
The chief points of interest are as follows: The mitosis in Oedogonium 
agrees with that of higher plants; the development of chromosomes out of the 
nuclear network, the formation of the nuclear plate, the longitudinal splitting of 
the chromosomes, the reconstruction of daughter nuclei seem like these pr 
in Fritillaria and Leucojum, two forms which were also studied by von WISSE- 
LINGH. In Oedogonium, the chromosomes, 19 in number, and differing greatly 
from one another in length, are connected by fine fibrils, The nucleolus does not 
take part in forming chromosomes, but disappears at the beginning of mitosis, 
and there appear in daughter nuclei new nucleoli, which later unite into one.— 
SHIGEO YAMANOUCHI 
Mycorhiza.—PEKLo announces in a preliminary paper’ the results of his 
Studies on the epiphytic mycorhiza of Carpinus and Fagus, with brief reference 
also to the endophytes of Alnus glutinosa and Myrica Gale. 
Tn Carpinus, asa reaction to the penetration of the tissues of the young rootlet, 
‘annins increase (as the author has also determined for Monotropa*), and this 
Testricts the fungus to the intercellular spaces. Nourishing itself partly on this 
Slucoside and other foods in the cortex, the fungus forms the jacket, the outer- 
most hyphae of which often die. Isolation of the fungus was finally accomplished 
by using a decoction of old thick mycorhizas, which proved very specific for the 
Sa easy oe 
° WISSELINGH, C. von, Ueber die Karyokinese bei Oedogonium. Beih. Bot. 
Centralbl. 2 32139-156. pl. 7. 1908. 
"PEKLO, J., Beitrage zur Lésung des Mykorhiza-Problems. Ber. Ie icosua 
Bot. Gesells. 27 3239-247. 1909. : 
ie a eo » Die epiphytischen Mykorhizen nach neuen Untersuchungen. I. M _ 
Ypopitys L. Bull. Bohm. Akad. Wiss. 00:000. 1908. 
