1912] CURRENT LITERATURE 449 
that the so-called Araucarioxyla of the earlier Mesozoic have nothing to do with 
the evolution of the stock from which A gathis and Araucaria have been derived. 
Walchia and Voltzia from the Permian and Trias, moreover, do not present the 
Araucarioxylon type of wood. The situation thus becomes difficult indeed for 
those who believe the Araucariineae to be the oldest conifers, and to constitute 
the articulation of the family with the Cordaitales.—E. C. JEFFREY. 
Cytology of the Chytridineae.—Batty,” working in STRASBURGER’S 
laboratory, has added much of importance to our knowledge of the cytology of 
the Archimycetes. In Synchytrium taraxaci the primary nucleus divides, not 
by mitosis as in S. decipiens and S, puerariae, which have been investigated by 
STEVENS and KusANo, but by a process analogous to nuclear gemmation, in 
which masses of chromatin originally derived from the nucleolus pass into the 
cytoplasm as chromidia which later become the basis of the secondary nuclei. 
While the stages in this process are not fully worked out, there can be little 
doubt from the figures showing the old primary nucleus still undivided, together 
with scores of secondary nuclei in the same parasite, but that the description 
given is substantially correct. These nuclei later divide by mitosis and always 
have four chromosomes. Curiously enough the conspicuous asters (“karyoder- 
matoplasts”’) which reconstruct the nuclear membrane in S. decipiens and S. 
puerariae appear to be absent from S. faraxact. 
BALty does not follow PERCIVAL® in including Chrysophlyctis in Synchy- 
L’s account of the 
remarkable amitoses in the resting sporangia of that plant. Here nuclear 
gemmation reaches its climax. The extruded chromidia never organize 
secondary muclei, but pass unchanged into the zoospores, which are formed in 
a most peculiar manner, while the remains of the primary nucleus still persist 
undivided in the center. Here again more details would be very welcome, but 
it is clear from the figures, together with those of PERCIVAL, that there is some- 
thing here far different from the ordinary behavior of nuclei, og better of chro- 
matin, for such cysts may be said to have no nuclei, though rich in chromatin, 
In Urophlyctis Riibsaamenii, amitosis, largely by nuclear gemmation of 
which figures showing details are presented, appears to be the sole method of 
nuclear multiplication. The cytological condition of this plant contrasts 
omit with that of the two preceding, in that the parasite becomes coenocytic 
the beginning of growth. On the basis of such differences he separates 
Hy Archimycetes into two series: one essentially uninucleate, including 
Synchytrium and Chrysophlyctis; the other coenocytic from almost the begin- 
ning, including the Cladochytriaceae, and more doubtfully the Rhizidiaceae 
1 BALLY, WALTER, — Studien an Chytridineen. Jahrb. Wiss. Bot. 
50: ee a 1-5. figs. 
L, JOHN, peice wart disease: the life history and cytology os a 
trium patie (Schilb.) Percl. Centralbl. Bakt. 25:440-446. pls. 1-3. 
