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1903] CURRENT LITER A TURE 445 



NaCl or the dilution of the nutrient solution produces fewer roots and shoots, 

 narrower and shorter leaves with slower development, stronger thickening of 

 the root elements, and a relative increase in the number of bundles. The 

 presence of NaCl is accompanied by the formation of leaves with fewer air- 

 spaces, and more palisade tissue, chlorophyll, and wax. Dilution of the 

 nutrient solution causes an increase in the length of the roots. Niirogen- 

 free solutions favor the development of stems. The reader observes in 

 the different cultures a variation of osmotic pressure which does not enter into 

 the author's discussion. This of course makes the results at least questionable. 



L. M. Snow. 



A HYBRID COTTON obtained by crossing Gossypium barbadcnse and G, 

 herbaceum has been studied by Cannon." The investigations deal with the 

 ^ two mitotic divisions by which the microspore mother cell gives rise to the 



four microspores. In practically all anthers of the hybrid cotton both nor- 

 mal and abnormal conditions are present. In normal microspore mother 

 cells the first nuclear division is heterotypic, the second homotypic; and the 

 two divisions are the exact homologues of these divisions in pure races of 

 plants. The two sizes of the chromatin rings or loops found in hybrid pigeons 

 and in some pure forms in plants were not found in the hybrid cotton. 

 The behavior of the chromatin at the tirst division could not be traced with 

 suflficient accuracy to determine whether the two daughter nuclei were of 

 pure or of mixed descent. If the paternal and maternal chromatin is segre- 

 gated as a result of the two mitoses in the microspore mother cell so as to 

 form nuclei with unisexual chromatin, such an organization of the chromatin 

 would form a morphological basis for variation in accord with the Mendelian 

 laws. Many abnormal cells were observed, but these degenerate before the first 

 division of the microspore mother cell. Amitosis is not rare and is probably 

 a factor which leads io infertility. A few mother cells showed two spindles, 

 as described by other writers on hybrids, but in the hybrid cotton such cells 

 degenerate before the first nuclear division is complete. — Charles J, 



Chamberlain. 



A THIRD REPORT on the marine resources of Hokkaido has been published 

 by the Fishery Bureau of the Hokkaido government, Japan. It is devoted 

 to the Laminariaceae and the Laminaria industries of the island and con- 



stitutes a volume of 212 pages illustrated by 41 plates. This is a very 

 important contribution to our knowledge of the kelps, but as it is printed in 

 the Japanese language it must remain somewhat inaccessible to most students. 

 The volume contains three papers; (i) on the Laminariaceae of Hokkaido, 

 by Professor Kingo Miyab6 ; (2) on the Laminaria industries of Hokkaido, by 

 Shin Yanagawa; and (3) chemical analyses of Laminaria, by Professor Kin- 

 taroOshima. In each of these the material is almost altogether original, and 



^Cannon, William A., Studies in plant hybrids: The spermatogenesis of hybrid 

 cotton. Bull. Torr. Bot. Club 30: 133-^72. pls. r-5. 1903- 



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