No. 1, August, 1920] CYTOLOGY 17 



115. Waller, A. E. Xenia. School Sci. Math. 19: 150-157. Feb., 1919.— Historical 

 and popular account of xenia, from both a genetic and cytological standpoint. Several il- 

 lustrations of xenia given, and simple demonstration experiments with maize characters, of 

 instructional value, suggested. [Sec also Bot. Ahsts. 5. Entry 496.] — Orland E. White. 



CYTOLOGY 



Gilbert M. Smith, Editor 

 George S. Bryan, Assistant Editor 



116. Bobilioff, W. De inwendige bouw der schorselementen ven Hevea brasiliensis. 

 (The structure of cell elements in the bark of Hevea brasiliensis.] Arch. Rubbercult. Neder- 

 landsch-Indie' 3 : 222-231. 1919.— See Bot. Absts. 5, Entry 546. 



117. Carter, Nellie. The cytology of the Cladophoraceae. Ann. Botany 33: 467^78. 

 / pi., 2 fig. 1919. — The chloroplast in Cladophora, Chaetomorpha and Rhizoclonium consists 

 of a parietal film lining the cell wall and often more or less reticulated. Pyrenoids are very 

 numerous and scattered in both the peripheral and internal parts of the chloroplast. The 

 nuclei are confined almost invariably to the chloroplast, not being found as a general rule in 

 the colorless cytoplasm. During mitosis the nucleus of Rhizoclonium and Cladophora is char- 

 acterized by the formation of a long thin spireme, which gives rise to very numerous chromo- 

 somes. After the migration of the chromosomes to the opposite poles of the spindle the daugh- 

 ter nuclei are separated by constriction of the spindle in the region of the equator. — G. S. 

 Bryan. 



118. Carter, Nellie. On the cytology of two species of Characiopsis. New Phytol. 

 18: 177-186. 3 fig. 1919. — Characiopsis saccata n. sp. and Ch. Naegclii (A. Br.) Lemm. are 

 treated. The cytological features of the vegetative cells were found to differ in important 

 respects in the two species. Zoogonidangia were not found. The cytology of Char actum 

 angustum is also described, in which the regular successive cleavage of the protoplast con- 

 trasts strongly with the progressive cleavage found in Ch. Sieboldii by Smith. — /. F. Lewis. 



119. Chambers, Robert. Changes in protoplasmic consistency and their relation to cell 

 division. Jour. Gen. Physiol. 2: 49-68. 1919. — The author has continued his microdissection 

 studies with dividing eggs of Arbacia and Asterias. Periodic changes in the consistency of 

 the egg cytoplasm after fertilization and during cleavage are described. It is shown that 

 the development of the amphiaster is associated with the formation of two semisolid masses 

 within the more fluid egg substance. After the cleavage furrow has completed the separa- 

 tion of the two blastomeres, the semisolid masses revert to a more fluid state. By various 

 treatments the formation of a cleavage furrow may be prevented following which the egg 

 reverts to a single, spherical, semifluid mass with two nuclei. An egg mutilated in its semi- 

 solid state may revert to a more fluid state in which case the furrow becomes obliterated, the 

 nuclei tend to more to positions which may assure symmetry in aster formation and a new 

 cleavage furrow is developed, or the cleavage furrow may persist until cleavage is completed, 

 cutting off non-nucleated segments. — O. F. Curtis. 



120. Coulter, M. C. A new conception of sex. [Rev. of: Jones, W. N. On the nature 

 of fertilization and sex. New Phytol. 17: 167-188. 1918. (See Bot. Absts. 3, Entry 637.)] 

 Bot. Gaz. 68:68-69. 1919. 



121. Gatenbt, J. Bronte. Identification of intracellular structures. Jour. Roy. Mi- 

 crosc. Soc. London 2 : 93-119. 14 fig. 1919. — The author tries to show certain results in prac- 

 tical histo-chemistry from the cytologist's point of view. Every animal cell is composed of 

 the following fairly sharply marked bodies; nucleus, cytoplasm and centrosome. The cyto- 

 plasm is composed of (1) protoplasmic or living inclusions such as mitrochondria, Golgi appar- 

 atus and possibly other less numerous enigmatic protoplasmic granules; (2) deutoplasmic 



BOTANICAL, ABSTRACTS, VOL. V, NO. t 



