1919] CURRENT LITERATURE 485 



unequal cell divisions by which unlike daughter cells arise, one of which 

 possesses ability to produce anthocyan, the other lacking it. In all future 

 divisions of the anthocyanin-producing mutated cells, the daughter cells also 

 inherit the power to produce the color. The contiguous mass of colored cells 

 in a sectional, mottled, or pulverulent pattern is considered the product of a 

 single mutant cell. If the mutation occurs at a very early stage in the life of 

 the plant, sectorial coloration is likely to result. If somewhat later, after the 

 main organs have been laid down, the mottled pattern results. When the cell 

 mutation occurs very late, so that only a few daughter cells are formed by each 

 mutant, the pattern is pulverulent. 



Patterns of the second group, rounded areas, and flecks of anthocyanin 

 occur more rarely than those of the first group. Comparison of these patterns 

 with the first indicates that they do not arise by cell mutation. Using seed 

 crystals as an illustration, he suggests the possibility that at certain points 

 anthocyanin-producing "seed colloids" of unknown composition arise, and that 

 around these central points aggregation continues, molecules or molecular 

 groups coming from surrounding cells, which are thus left colorless. This 

 hypothetical colloidal substance would have some direct or indirect relation 

 to the production of anthocyanin, either as a source of building material, or 

 as a catalytic agent. — Chas. A. Shull. 



Quantitative nature of sex. — Schaffner" has published some significant 

 observations on sex intermediates. The white mulberry shows about 40 per 

 cent pure staminate plants, 40 per cent carpellate, and 20 per cent intermediate 

 in all gradations. Among the last, the most interesting example consists of a 

 pure staminate tree with a single, almost pure carpellate branch, showing 

 "that a sex reversal can and sometimes does take place in an old tissue whose 

 cells are removed by thousands of vegetative divisions from the original zygote. 

 It assures us that sex control is only a matter of finding out how to change the 

 prevailing physiological state." The peach leaf willow showed only 9 per cent 

 intermediates. These were primarily staminate, but had many catkins which 

 were staminate only at the base and became carpellate at the end. "But on 

 the transition zone, between the staminate and carpellate parts", the axis 

 seemed to be neutral in regard to sex, and here bisporangiate flowers were 

 frequently present." Also, in this neutral zone abnormal flowers were very 

 frequent, structures developing which were partly staminate and partly car- 

 pellate. These observations serve to support the conclusions published by the 

 author in 1910 to the effect that "sexuality is a condition and not a character" 

 (factor) . Observations of much the same nature have recently been published 

 by Stout.'^ — Merle C. Coulter. 



" ScHAFFNER, JOHN H., The nature of the dioecious condition in Morus alba 

 a.nd Salix amy gdalo ides. Ohio Jour. Sci. 19:409-416. 1919. 



■3 Stout, A. B., Intersexes in Plantago lanceolata. Bot. Gaz. 68:109-133. 

 ph. 12, 13. 1919. 



