No. 2, March, 1921] FOREST BOTANY AND FORESTRY 109 



remain visible for some time, and soon take on a more or less definite polar orientation. 

 Lateral pairing of the threads begins at their free ends and gradually involves all parts. The 

 granules or thickenings of the associating threads show a correspondence in position, which 

 gives them the appearance not only of tetrads such as Schoenfeld thought to be of peculiar 

 significance here, but also of dyads, hexads, and octads. As the threads pass into the pachy- 

 nema stage these thickenings gradually become less conspicuous. The interpretation of 

 Schoenfeld is attributed in large part to faulty fixation. — L. W. Sharp. 



739. Yamaha, Gihei. Einige Beobachtungen uber die Zellteilung in den Archesporen und 

 Sporenmutterzellen von Psilotum triquetrum Sw. mit besonderer Rucksicht auf die Zell- 

 plattenbildung. [Some remarks on the cell division in the archesporial and spore mother cells 

 of Psilotum triquetrum Sw. with special regard to the formation of the cell plate.] Bot. Mag. 

 Tokyo 34: 117-129. 20 fig. 1920.— The cells of Psilotum are specially adapted for cytologi- 

 cal work because of the large nuclei, that are rich in chromatin. The rod-shaped elements 

 of the cell plate are very persistent. In the heterotypic division of the archespore the so-called 

 nucleolar substance could be traced near the daughter nuclei. The phragmoplast can be 

 traced back to the chromosome-connecting filaments. These filaments divide longitudinally, 

 starting at the equatorial plane. At this stage a large number of "extranucleoli" were ob- 

 served. The daughter nuclei approach each other more or less; the cell plate becomes more 

 conspicuous; while its granular contents, the dermatosomes, are very clear. In the meiosis 

 no "radial fibres" were observed. The dermatosomes seem to be used up in the forma- 

 tion of the cell plate, which precedes the simultaneous formation of the cell wall. The 

 homeotypic division shows the same peculiarities. The shrinkage of the wall of the spore 

 mother cell seems to cause the separation of the tetrads. — L. G. Baas-Becking. 



FOREST BOTANY AND FORESTRY 



Raphael Zon, Editor 

 J. V. HoFMANN, Assistant Editor 



740. Adamson, R. W. The Bartram oak. Sci. Amer. 122:301. 1920.— See Bot. Absts. 

 6, Entry 1564. 



741. Algan, H. Bibliographie. [Rev. of: Huffel, G. Economie forestiere. (Forest 

 economy.) Tome premier, deuxieme volume, deuxieme edition. 4^^ p. 1920.] Bull. Trimest. 

 Soc. Forest. Franche-Comte et Belfort 13 : 196-202. 1920.— Nearly two-thirds of this impor- 

 tant work is devoted to a discussion of the history of forest property and forest legislation 

 from the beginning of the feudal period to the middle of the nineteenth century. Forest 

 policy is discussed at some length, including the relation of forests to the public welfare, pub- 

 lic control of private cuttings, public assistance to private owners, forest taxation, etc. The 

 final part of the volume contains a wealth of statistics as to the extent, distribution, and 

 ownership of French forests. — S. T. Dana. 



742. Andrews, F. M. Some trees of Indiana. Proc. Indiana Acad. Sci. 1918:261-263. 

 1920. 



743. Anonymous. The forestry commission. Nature 105:215-216. 1920.— Outline of 

 program for 1919-20 with personnel of consultative committees for England, Scotland, Wales, 

 and Ireland. About 34,000 acres of afforestable land are being acquired. — 0. A. Stevens. 



744. Anonymous. Forestry, tree diseases and timber. [Rev. of: (1) Boerker, R. H. D. 

 Our national forests. A short popular account of the work of the United States forest service 

 on the national forests. XIV+ 2S8 p. Macmillan and Co. : London and New York, 1918. 

 (2) Stebbing, E. p. Commercial forestry in Britain: its decline and revival. VI + 186 p. 

 John Murray: London, 1919. (3) Webster, A. D. National afforestation, 160 p. T. 

 Fifiher Unwin: London, 1919.] Nature 105: 577-579. 1920. 



