No. 2, December, 1921] CYTOLOGY 71 



446. Dragoixj, J., et F. Vlbs. Les consequences cytologiques do I'arret osmotique de 

 la division cellulaire. [The cytological consequences of the arrest of cell-division by osmotic 

 pressure.] Compt. Rend. Acad. Sci. Paris 172: 1210-1211. 1921. — Cytological studies are 

 reported supporting experimental results on the effect of osmotic pressure on cell-division 

 [see Bot. Absts. 10, Entry 45S].— C. //. Farr. 



447. D[udgeon], W[infield]. [Rev. of: Gates, R. Rugglbs. A preliminary account 

 of the meiotic phenomena in the pollen mother-cells and tapetum of lettuce (Lactuca sativa). 

 Proc. Roy. Soc. London B. 91 : 21C-223. 2 fig. 1920 (see Bot. Absts. 6, Entry 1674).] Jour. 

 Indian Bot. 2: 151-152. 1921. 



448. GuiLLERMOND, A. Observations vitales sur le chondriome des vegetaux et recherches 

 sur I'origine des chromoplastes et le mode de formation des pigments xanthophylliens et caro- 

 tiens. Contribution a I'etude physiologique de la cellule. [Intra-vitam observations on the 

 chondriome of plants and researches on the origin of chromoplasts and the mode of formation 

 of xanthophyll and carotin pigments. Contribution to the physiological study of the cell.] Rev. 

 Gen. Bot. 31: 372^13, 44fi-50S, 532-603, C35-770. 60 pL, So fig. 1919.— A comprehensive 

 treatment is presented of plant chondriosomes with special reference to the formation of 

 xanthophyll and carotin pigments. It includes not only a summary of previous contributions 

 by the author and a consideration of new observations, but also an extensive review of chon- 

 driosome literature. — Many species of flowering plants were examined, the most favorable 

 being Tulipa suaveolens, T. Gesneriana, and 7ns germanica. Epidermal and mesophyll cells 

 of sepals, petals, bracts, and other floral organs were studied in the living condition as well 

 as by means of the special fixing and staining methods commonly used in the investigation 

 of these objects. Benda's method of fixation followed by iron-haematoxylin or Kull's 

 staining method proved successful. Osmic acid alone also conserves faithfully the cyto- 

 plasmic structures. — The cytoplasm is described as a homogeneous, more or less hyaline sub- 

 stance, probably colloidal in nature, filled with chondriosomes in the form of granular mito- 

 chondria, short rods, and elongated (sometimes branched) chondrioconts. These elements 

 are formed only by division of preexisting chondriosomes. They are protoplasmic in nature 

 and play an important physiological role, since through them alone certain products ar& 

 elaborated. — In older cells the chondrioconts (rod- or thread-like chondriosomes) increase in 

 size and become plastids. In cellular degeneration the chondrioconts and bodies derived from 

 them break down into granular masses, and with this degeneration is often associated the ap- 

 pearance of fatty substances. The behavior of cytoplasmic inclusions can be studied in the 

 living cells without fixation. Formation of carotin and xanthophyll pigments is associated 

 with the chondriosomes and plastids derived from them. The pigments may occur within 

 these bodies in the form of minute granules or crystals; in some chromoplasts they appear 

 to be in a diffused state. The presence of fat globules and the temporarj' appearance of starch 

 within the developing chondrioconts are frequently associated with pigment formation. There 

 seems, however, to be no constant relationship between oil formation, starch formation, and 

 the development of chlorophyll and other pigments. — The author argues strongly for the con- 

 ception of the plant chondriosome as a self-perpetuating cell organ concerned in the develop- 

 ment of plastids and in the elaboration of starch, oil, and pigments in a manner analogous to 

 similar phenomena in animal cells. He replies to the objections advanced by other writers 

 against this view and regards as inadequate the evidence for the existence of 2 or more dis- 

 tinct categories of chondriosomes and for their nuclear origin. — L. F. Randolph. 



449. Levy, F. Die Kernverhaltnisse bei parthenogenischen Froschen. [Nuclear phenom- 

 ena in parthenogenetic frogs.] Sitzungsber. Preussisch. Akad. Wiss. Berlin 1920: 417-425. 

 1920. 



450. LicBNT, E. Sur la structure et revolution du noyau dans les cellules du meristeme 

 de quelques Euphorbiacees. [Structure and development of the nuclei of meristematic cells 

 of certain Eurphorbiaceae.] Compt. Rend. Acad. Sci. Paris 172: 10G3-1066. 1921.— Root- 

 tips, stem tips, young leaves, pollen-mother-cells, and developing embryo-sacs were studied. 

 The nucleole sometimes persists through the anaphases and then disappears without leaving 



