416 BOTANICAL GAZETTE [NOVEMBER 
primarily upon physiognomy, and only secondarily upon environment or 
floristic composition. It is doubtful whether such a method can ever give 
entirely satisfactory results, although the author considers it the best for this 
region, where all the associations show the effect of cultural changes. Probably 
the gravest defect of the paper is the entire failure of the author to discuss 
the dynamics of the vegetation. The development of the various associations 
and their successional relations are omitted completely. Illustrations would 
have added greatly to the clearness of the descriptions, and the scale of the 
accompanying map would have easily permitted the location of the chief 
types of vegetation. Almost half of the ate article is occupied by a care- 
fully annotated list of species—H. A. GLE ; 
Gametophytes and embryo of Pseudolarix.—MrvakeE and YasurI* have 
investigated the monotypic Pseudolarix (P. Kaempferi), a native of China, 
one of the Abietineae whose morphology had not been studied. The material 
was obtained from a tree growing in a garden in Pallanza, Italy. The winged 
grains contained the usual cells of the male gametophyte, and the 
divisions showed 12 chromosomes, but the later development of the game- 
tophyte was not seen. Megaspore formation was observed, a linear tetrad 
being formed about the time of pollination (April in Italy). The large central 
vacuole is formed in the spore stage (before free nuclear division), and the 
young female gametophyte is invested by several layers of nutritive cells. 
At maturity, the megaspore membrane is well developed, as in other Abieti- 
neae. Early in June the female gametophyte is solid tissue, and then the § 
or 6 archegonium initials appear, the archegonia maturing in about three 
weeks. After the division of the central cell, the ventral canal cell disorganizes 
at once. Fertilization occurs about the end of June, and the first four free 
nuclei of the proembryo move to the base of the egg, walls appearing with the — 
next division. The cells of each tier divide, and the completed proembryo 
consists of four tiers, with four cells in each tier. The functions of the tiers 
are as in Pinus, and the whole situation seems to be an almost exact duplica- 
tion of that genus.—J. M. C 
A cedar bog in Ohio.—Dacunowskr* records, as an isolated area of 
northern plants, left behind in the great northward migrations following upon 
the retreat of the ice sheet of the glacial period, a swamp in central Ohio, 
characterized by Thuja occidentalis and other species not usually found south 
of central Michigan. Mats of sphagnum, together with the sundew and various 
orchids, testify to the true bog character of the association —Gro. D. FULLER. 
3 Mixayi, Kiicut, and Yasur, Kono, On = oe and embryo of Pseu- 
dolarix. Ann. Botany 25:639-647. pl. 48. 1 
*4 DACHNOWSKI, ALFRED, A cedar bog in AOE Ohio. Ohio Naturalist 11: 193- 
199. IQII. 
