1918] CURRENT LITERATURE 401 
Endodermis and prothallium of Equisetum.—Kasnyap* has investigated 
the endodermis and prothallium of Equisetum debile. He finds that the 
endodermis is very unstable. At the nodes of the subterranean and aérial 
sterile shoots, and in the fertile region, the endodermis invests each vascular 
bundle, while in the internodes of the subterranean and aérial sterile shoots 
occasionally fuse, leaving islands of parenchymatous tissue. In the case of the 
prothallium, he discovered that if the spores are sown thickly, the prothallia 
remain small, develop only one growing point, and usually bear only one kind 
of sex organ. If the spores germinate at a distance from each other, the pro- 
thallia become very large and develop a meristem around the margin. It is 
somewhat remarkable that in this latter case the prothallia produce archegonia 
first and antheridia later.—J. M. C 
Variation in Picea excelsa.—A delayed volume of Acta Horti Bergiana 
contains a remarkable series of illustrations of variations in seedlings, leaves. 
and especially in the ovulate cones of Picea excelsa3s Most of the plates are 
double and many of them are beautifully colored, and the number of separate 
figures averages between 30 and 4o to a plate. The immense amount of 
variation shown in these figures doubtless would have induced many writers 
to multiply species. The present account consists of the figures and a good 
description of plates. There is scarcely a page of text. Even as it is, the 
illustrations are valuable as a record, and WITTROCK may give a full account 
ater.—CHARLES J. CHAMBERLAIN. 
Vegetation of Ohio.—Miss BRAUN*® has studied the vegetation of Ohio as 
seen in the Cincinnati region, classifying the plant associations according to 
the physiography into the upland, slope, valley, and floodplain series. All 
the successions progress toward the mesophytic forest, the climax being either 
a forest of Fagus on the pre-erosion topography, or a mixed mesophytic forest 
upon the floodplains and in the ravines. She is of the opinion that this erosion 
climax, which resembles the forest of the southern Appalachians, is the more 
permanent and will eventually displace the pre-erosion climax beech forest. 
The report is well illustrated with photographs, maps, and diagrams.—Gero. 
D. FuLier. 
Addisonia.—The fourth number of the second volume of this journal, with 
its “colored illustrations and popular descriptions of plants,” includes t 
% Kasnyap, S. R., Notes on Equisetum debile Roxb. Ann. Botany 31:430-445- 
Sigs. 3. IQI7. 
3s Wittrock, V. B., De Picea excelsis (Lam.) Lk., praesertim de formis suecicis 
hujus arboris. Pars I. Meddelanden om granen. Acti Horti Bergiani 5§:1-o1 
pls. 1-23. 1914. 
% Braun, E. Lucy, The physiographic ecology of the Cincinnati region. 
Biol. Surv. 2:(Bull. 7) 116-211. figs. 58. 191 
Ohio 
