1912] CURRENT LITERATURE 260 
phyceae are the next younger group of algae, descended partly from Rhodo- 
phyceae and partly from flagellate-like organisms. (5) The Zygophyceae are 
derived from flagellated ancestors, the Peridinales being most nearly related to 
the modern flagellates. (6) The Chlorophyceae are the youngest of the algae, 
and have come partly from Rhodophyceae and partly from flagellated ancestors. 
—S. YAMANOUCHI. 
Sporangia and spores of Aneimia.—Srrevens® has investigated the 
development of the sporangia and spores in a species of Aneimid. He finds 
that the two tapetal layers break down at the mother cell stage, freeing the 
protoplasts and resulting in a tapetal plasmodium, as among the Ophioglossales. 
It was in connection with work on Botrychium (1906) that STEVENS proposed 
the excellent descriptive phrase “tapetal plasmodium.” Perhaps it was a slip 
that he did not include this earlier paper in the “‘literature cited,” or the still 
earlier paper of CARDIFF (1905). Upon the separation of the mother cells in 
Aneimia the plasmodium entirely surrounds each one. As each mother cell 
lies imbedded separately in the plasmodium, no wall is seen, and when the 
tetrad is formed the mother cell membrane persists about it. At the separa- 
tion of the spores of a tetrad, the tapetal plasmodium flows between them. 
The author thinks that sis thickness of the exine “is the work of the tapetal 
plasmodium.”’ It is becoming more and more evident that in structure and 
behavior the Cpaeke: be and Filicales belong together.—J. M. C 
Chromosomes in maize.—Kuwapa® has studied the nuclear conditions 
in the pollen mother cells of nine different races of corn: red starch corn, yellow 
starch com, amber rice popcorn, black starch corn, golden broach field corn, 
white flint corn, sugar corn, early light sugar corn, and red sugar corn. The 
number of gemini in these different races varies from g to 12, the sugar corns 
having generally a larger number than the starch corns. He thinks that the 
smaller number was reduced from 12, which is the original number for all the 
races of Zea Mays. The size and shape of the gemini in a figure differ, and there 
is present always a duplication of each of the gemini. In the equatorial plate 
of the homotypic division some pairs of chromosomes come in contact with 
each other. He suggests that the production of innumerable races of Zea Mays 
might have a certain relation to the duplication of chromosomes, resulting in 
the double number derived from the original form, which had probably 6 
chromosomes as the reduced number.—S. YAMANOUCHI. 
Botryopteris antiqua.—This interesting paleozoic fern, described by 
KipsTON in 1908 from inadequate material, has been studied by Miss BENSON? 
ENS, WILLIAM CuAseE, On the development of the 4a and spores of 
datece hse Ann. Botany 25:1059-1008. pis. 84, 85. 19 
%* Kuwapa, Y., Maiosis in the pollen mother cells of Zea a L. Bot. Mag. 
Tokyo sales Hg pl. 6. figs. 4. 1911. 
3 BENSON, MARGARET, New gb on oan ae antigua Kidston, Ann, 
Botany 25: ee. fies. 3. pis. 82-03. I 
