106 CYTOLOGY [BoT. Absts., Vol. VII, 



725. Farr, Wanda Kirkbride. Cell-division of the pollen-mother-cell of Cobaea scan- 

 dens alba. Bull. Torrey Bot. Club 47:325-337. PI. U. 1920.— A review is given of lit- 

 erature on cytokinesis in pollen-mother-cells with special reference to cell-plate formation 

 and cleavage. Author reports that in Cobaea scandens alba furrowing was observed in 

 formation of the tetrad, but that the cell-plate was not apparent during cytoplasmic division. 

 — P. A. Mum. 



726. Gates, R. R. The structure of the nucleus. [Rev. of: Agar, W. E. Cytology: 

 with special reference to the metazoan nucleus. XII + ^H p. Macmillan and Co. : London, 

 1920.] Nature 105:482-483. 1920. 



727. Gaudissart, P. Reseau protoplasmique et chondriosomes dans la genese des myo- 

 fibrilles. [Protoplasmic reticulum and chondriosomes in the genesis of muscle fibers.] 

 La Cellule 30: 29-43. 2 pi. 1915-1919. — An investigation of the roles played by (1) the 

 reticular or alveolar protoplasmic substratum and (2) the granular elements (mitochondria) 

 in the development of muscle fibers in the chick embryo, each element having been held to 

 be exclusively responsible by different workers. The author concludes "that the muscle fibers 

 arise neither exclusively from a protoplasmic reticulum, nor exclusively from mitochondria 

 or other granular elements, but that they result from the cooperation of mitochondria with 

 a reticular structure, different, at least at first, from the mitochondria themselves. It is the 

 reticulum .... which, in orienting itself, furnishes the chief outline of the muscle 

 fibers; but, on their part, the mitochondria, in fixing themselves on this reticulum, furnish 

 certain substances which are incorporated in it and contribute to the development of the 

 myofibrils." It is not true that "each myofibril is only a modified filamentous chondriosome" 

 (Dtjesberg). — L. W. Sharp. 



728. GuiLLiERMOND, A. Sur I'origine mitochondriale des plastides a propos d'un travail 

 de M. Mottier. [Concerning the mitochondrial origin of plastids with regard to Mottier's 

 work.] Ann. sci. nat. bot. X. 1:225-246. 5 pi., 10 fig. 1919. — Author considers as inexact 

 Mottier's view based upon a study of meristematic cells in pea, that mitochondrial elements 

 and "plastid primordia" are distinct and independent entities in cytoplasm. An a priori 

 objection to Mottier's theory is that in animals mitochondria appear to be concerned 

 in elaboration of products of secretion of cell, acting similarly to plastids; and, moreover, a 

 majority of animal pigments originate in mitochondria. Author then points out that size 

 is no reliable criterion for distinguishing mitochondria and "plastid primordia" as Mottier 

 argues. Mitochondria vary in size, and he has observed such cytoplasmic bodies in ani- 

 mals of similar size to those in plants that are "plastid primordia." In general, author con- 

 siders that diverse forms of mitochondria have a common origin and, in particular, plastids 

 have a mitochondrial origin. — J. P. Kelly. 



729. GuiLLiERMOND, A. Observations vitales sur le chondriome d'une Saprolegnicacee. 

 [Observations of chondriosomes in a living Saprolegnia.] Compt. Rend. Acad. Sci. Paris 

 170: 1329-1333. 5 fig. 1920. — Granules, rods, and filaments are made visible in the living 

 material by staining with neutral red and cresyl blue. The latter differentiates the meta- 

 chromatic bodies from the chondriosomes. — C. H. Farr. 



730. Hartmann, Max. Untersuchungen iiber die Morphologie und Physiologic des 

 Formwechsels (Entwicklung, Fortpfianzung, Befruchtung und Vererbung) der Phytomonadinen 

 (Volvocales). Programm der Untersuchungen und I. Mitt.: tjber die Kern- und Zellteilung 

 von Chlorogonium elongatiun Dangeard. [Investigations on the morphology and physiology of 

 variation in form (development, reproduction, fertilization, and heredity) of the Phytomona- 

 dineae (Volvocales). Program of the investigation and first contribution; On the nuclear and 

 cell division of Chlorogonium elongatimi Dangeard.] Arch. Protistenk. 39: 1-33. 3 pi., 2 fig. 

 1919. — After a short prospectus of a proposed series of investigations on the morphology 

 and physiology of the Phytomonadineae, the author proceeds to a description of cell and 

 nuclear division in Chlorogonium elongatum Dang. The first indication of cell division is 



