140 CYTOLOGY [Bot. Absts., Vol. VI, 



974. Owen, J. H. School natural history societies. I. Felsted School Scientific Society. 

 School Sci. Rev. [London] 1 : 42-44. 1919. — This society was founded in 1877 and has sections 

 in botany, geology, ornithology and other subjects. — A. Gundersen. 



975. Whitney, W. Science of plant life. [Rev. of: Transeatj, E. N. Science of plant 

 life. 386 p., 194 fig. World Book Co.: Yonkers-on-Hudson, New York, 1919.] Plant World 

 22:248-249. 1919. 



CYTOLOGY 



Gilbert M. Smith, Editor 

 G. S. Bryan, Assistant Editor 



976. Adams, J. F. Sexual fusions and development of the sexual organs in the Perider- 

 miums. Pennsylvania Agric. Exp. Sta. Bull. 160: 31-76. 5 pi. (1919.) 1920.— See Bot. 

 Absts. 6, Entry 1214. 



977. Allen, Charles E. The basis of sex inheritance in Sphaerocarpos. Proc. Amer. 

 Phil. Soc. 58: 289-316. 28 jig. 1919. — Plants of Sphaerocarpos Donnellii were successfully 

 cultivated under greenhouse conditions in pots kept in a Wardian case. Although modifica- 

 tions in the form of the thallus occur when plants are grown under cultivation, the changes 

 brought about by environmental conditions do not bring about any loss of function on the part 

 of the sex organs or of the gametes. Fertilization was easily secured and sporophytes were 

 formed in abundance. Spores of S. Donnellii invariably remained united in tetrads. The 

 differences which distinguish female from male plants result from differences in the spores that 

 are to give rise to them. Of the spores formed by the division of a single mother cell, two bear 

 female potentialities and two male potentialities. There was found to be no marked differ- 

 ence between female producing and male producing spores in their capacity for germination, 

 but a difference in the rate of germination was noted. Cells of the female gametophyte gave 

 eight chromosomes, of which one is much longer and thicker than any of the others; the 

 remaining seven differ in length among themselves. Seven of the chromosomes of the male 

 also vary in length among themselves and seem to correspond to the seven smaller ones of 

 the female; the eighth chromosome of the male is very small. Of the four nuclei formed in 

 the spore mother cell, two sister nuclei and spores receive a large chromosome each. Since 

 the large chromosome is always present in the cells of the female and never in those of the 

 male, a spore receiving a large chromosome necessarily develops into a female gametophyte; 

 a spore receiving a small chromosome develops into a male gametophyte. The sex chromo- 

 somes of Sphaerocarpos are compared to the X and Y chromosomes of animals, the female 

 possessing in this case an X element, and the male a Y element. The size differences between 

 plants of opposite sex are determined by the difference in chromosome bulk which influences 

 the rate of cell growth and cell division. A second category of sex characters results from 

 other, still unknown, specific peculiarities of the sex chromosomes. [See also Bot. Absts. 4, 

 Entry 486.] — Wanda Weniger. 



978. Bezssonoff. Sur l'obtention experimentale de la sexualite chez les champignons et 

 orientee sur la structure typique du plasma sexuel. [On the initiation of sexual reproduction 

 in fungi by experimental means, and the existence of a cytoplasmic structure peculiar to the 

 sexual process.] Compt. Rend. Acad. Sci. Paris 170: 288-290. 1920.— See Bot. Absts. 6, 

 Entry 1344. 



979. Bryan, Geo. S. The fusion of the ventral canal cell and egg in Sphagnum subse- 

 cundum. Amer. Jour. Bot. 7: 223-230. 2 pi. 1920. — Author reviews briefly the literature 

 dealing with the archegonium of Sphagnum, with special reference to the egg and the ventral 

 canal cell. The ventral canal cell regularly persists and is very variable in size. Its proto- 

 plast and that of the egg round off and the wall between them disintegrates, the two cells 

 thus lying side by side in the venter of the archegonium. In a number of cases, in material 



