280 CYTOLOGY [Bot. Absts. 



1931. Alvarado, Saltjstio. La fina estructura de los vasos lenosos (Nota previo). [Mi- 

 nute structure of wood vessels.] Bol. R. Soc. Espafiola Hist. Nat. 19: 66-75. 7 fig. 1919. — 

 See Bot. Absts. 3, Entry 1567. 



1932. Bailey, Irving W. Phenomena of cell division in the cambium or arborescent 

 gymnosperms and their cytological significance. Proc. Nation. Acad. Sci. [U. S. A.] 5: 283-285. 

 July, 1919. — Growth and cell division in the cambium of woody plants seem to have been little 

 studied by other workers, probably because of the difficulty of sectioning. This paper re- 

 ports cytological phenomena observed in Pinus Strobus, the species with which the writer's 

 methods were perfected. The very long and slender cambium cells are uninucleate. In 

 "normal longitudinal divisions" the spindle is placed diagonally in the cell, and the mitotic 

 figure is asymmetrical. After nuclear division the spindle is extended lengthwise of the cell 

 by the addition of peripheral fibers, while the central fibers disappear and are replaced by 

 the cell plate. Thus two separate masses of fibers are formed, designated kinoplasmasomes. 

 These kinoplasmasomes gradually recede to the ends of the mother cell, which is then longi- 

 tudinally bisected by the cell plate. During the formation of the cell plate the daughter 

 nuclei remain near the center of the mother cell. — H. B. Frost. 



1933. Digby, L. On the archesporial and meiotic mitoses of Osmunda. Ann. Botany 33 : 

 135-172. PL 8-12. 1919. — Several species, but principally Osmunda palustris, were used for 

 this work. Fixing was done on warm days, about noon, and the material was plunged into 

 30 per cent alcohol at 30 C. for a few seconds before placing it in the fixing fluid. Most of 

 the illustrations are from material fixed in strong Flemming solution. — Considerable atten- 

 tion is given to the archesporial mitoses, especially the last sporogenous mitosis, immediately 

 preceding the reduction divisions, and all these mitoses were found to have the general char- 

 acter of vegetative divisions. A diagrammatic scheme, in color, makes it easy to understand 

 Miss Digby's interpretation. Each univalent chromosome has a dual nature which persists 

 throughout chromosome dissolution and reconstruction. Longitudinal fission occurs in late 

 anaphase. The parallel threads, seen in telophase of the last sporogenous mitosis, are iden- 

 tical with the parallel threads seen in prophase of the heterotypic mitosis. During synapsis 

 these parallel threads become closely associated and emerge from synapsis as a univalent 

 filament, but there may be a space in its substance, marking the line along which fission will 

 occur as the chromosomes separate during the homotypic mitosis. Segments of the univa- 

 lent filament become associated in pairs, and the two members of each pair are separated in 

 the heterotypic mitosis. The homotypic mitosis simply separates the two longitudinally 

 associated parts of each member of the pair, the splitting or fission of the chromosomes being 

 merely the reappearance of the fission which was seen in the daughter chromosomes of the 

 heterotypic telophase. — Charles J. Chamberlain. 



1934. Harper, R. A. The structure of protoplasm. Amer. Jour. Bot. 6: 273-300. 1919. 

 — Author brings together, from cytology, colloid chemistry and genetics, data which bear on 

 the problem of the chemical and physical characteristics of protoplasm. Emphasizes impor- 

 tance of the cell theory. — Modern cytology recognizes the existence of localized spatially dif- 

 ferentiated regions of the cell body (such as plastids) in which physiological processes take 

 place. It has given up the old "corpuscular" theories of the structure of protoplasm, though 

 these are still suggested by the modern discussions of chondriosomes and mitochondria. Chro- 

 mosomes have received intensive study and their importance in heredity has been established, 

 although we still know little about their structure or the means whereby they control the proc- 

 ess of development. — Following a recognition and study of the colloidal state of matter, the 

 earlier and cruder theories of the chemistry of protoplasm have been superseded by the con- 

 ception of the cell as a polyphase colloidal system, a conception which is in harmony with 

 many of the observed facts of cytology. It fails, however, to explain polarity, a conspicuous 

 characteristic of the living cell. — Evidence from genetics, and particularly from the Men- 

 delian hypothesis of unit factors, and the conception of the chromosomes as "so many chains 

 of factorial beads," tends to suggest the old and now refuted idea of spatial configuration in 



