238 FORESTRY [Bot. Absts., Vol. VII, 



V 



1 and 2 are used in young tissues, meristem, and ordinary adult tissue; 3 is used on resistant 

 tissues; and 4 and 5 for mitochondria. The formalin is usually added just before using. 

 Material may be left permanently in the fixative after adding a little water.— C. H. Farr. 



1615. Mangenot, G. a propos du chondriome des Vaucheria. [The chondriome of 

 Vaucheria.] Compt. Rend. Acad. Sci. Paris 170: 1458-1459. 1920.— In living material gran- 

 ules of various sizes are found among the chloroplasts, bodies that reach the size of chloro- 

 plasts and smaller motile bodies consisting of lipoids. In addition there are round grains, of a 

 dead appearance, mingled with short rods (the true mitochondria) that are always larger than 

 the fat bodies. Metachromatic corpuscles may also be distinguished by intra-vital stains.— 

 C. H. Farr. 



1616. Mangenot, G. Sur revolution des chromatophores et le chondriome chez les Flori- 

 dees. [The development of the chromatophores and chondriomes of the Florideae.] Compt. 

 Rend. Acad. Sci. Paris 170: 1595-1598. Fig. 1-11. 1920.— In the Lemaneaceae the rhodo- 

 plasts are elongated, the smaller ones resembling chondrioconts, but containing the pig- 

 ment material. These small rhodoplasts are found in the carpogonium, but after fertiliza- 

 tion they fragment into chondrisomal structures which persist until the formation of the 

 young carpospores, when they enlarge and the pigment reappears in the mature spore. An- 

 other tY9& of chondriosome remains unchanged throughout the life history of the alga.— 

 C. H. Farr. 



1617. Sharp, Lester W. Somatic chromosomes in Tradescantia. Amer. Jour. Bot. 7: 

 341-354. 2 pi. 1920.— Somatic chromosomes from the root tip of Tradescantia virginiana were 

 studied. The entire cycle of chromatin history is described in detail, beginning with the 

 metaphase. The author is particularly concerned with the time and method of chromosome 

 splitting and with the bearing of the observed facts on the problem of chromosome reduc- 

 tion. During telophase the chromosomes are transformed by irregular vacuolation into 

 alveolar-reticulate structures, and in the resting reticulum the limits of the constituent chro- 

 mosomes may sometimes still be made out. In prophase, the chromosomes separate from one 

 another and each gives rise to a single slender chromatic thread in v/hich the definitive split 

 develops as a new formation. This splitting has no relation to the vacuolation during telo- 

 phase, at which time the chromosomes must be regarded as single. Contrary to the conclu- 

 sions of some previous Vv-orkers, therefore, splitting is a phenomenon of the prophase rather 

 than of the telophase. No evidence has been found that chromosome splitting is a division of 

 smaller chromatic units. Chromosome behavior during somatic telophase does not pro- 

 vide a key to the interpretation of the reduction process.- £/. W. Sinnott. 



FORESTRY AND FOREST BOTANY 



Raphael Zon, Editor 

 J. V. HoFMANN, Assistant Editor 



1618. [Anonymous.] A. B. J. Australian hardwoods. [Rev. of: Baker, R. T. The 

 hardwoods of Australia and their economics, xvi + 522 p., 1 pi. Technical Education Series 

 No. 23. The Technological Museum: Sydney, 1919.] Nature 105: 802-803. 1920.— Australia 

 has probably the largest variety of hardwoods in the world, but representing less than 500 

 species. Nearly half of these belong to Eucalyptus, which supplies the bulk of hardwoods 

 for commercial purposes. Author emphasizes use of color in identification. Reviewer has 

 compared some of the plates with specimens and finds the representation good.— 0. A. 

 Stevens. 



1619. Anonymous. Awbury Arboretum. Brooklyn Bot. Gard. Rec. 9:23-24. 1920.— 

 Digest of article in Bull. Geog. Soc. Philadelphia (July, 1919).— See Bot. Absts. 7, Entry 77. 



