1920] CURRENT LITERATURE 471 



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In view of the important bearing of Beer and Arber's conclusions upon 

 various cytological and physiological problems, it is to be hoped that future 

 investigations may throw some light upon the following questions: 



1. Are Beer and Arber's phragmospheres actually hollow spheres of 

 kinoplasm or ring-shaped phragmoplasts such as occur in other tissues of the 

 higher plants i 



2. If they are ring-shaped phragmoplasts, as seems probable, do they 

 form cell plates ; 



3. Are the nuclei of the "binucleate cells" separated by a thin membrane, 

 or does the cell plate disappear without forming a membrane ? 



4. Do the nuclei of multinucleate cells arise by the same type of nuclear 

 division as the nuclei of binucleate cells ? — I. W. Bailey. 



Hepaticae. — Among recent publications on the Hepaticae by Evans are 

 the following. In continuation of studies of the New England Hepaticae, 3 

 three species of Nardia are fully discussed, one of them being described as 

 new. In continuation of the North American Hepaticae, 4 other species of 

 Nardia are considered, also additions to the flora of the United States, exten- 

 sions of range, and clearing up some difficulties in nomenclature. A taxonomic 

 study of Dumortiera* contains a full discussion of the two species as to structure, 

 classification, stations, and literature. 



A new Riccia 6 (R. bistriata) from Peru presents a noteworthy feature in 

 the peculiar bands of thickening which are found in the walls of the green 

 cells," a feature which has not before been noted in the Marchantiales. Three 

 species of Asterella 7 from South America are presented as new combinations, 

 transferred from Fimbriaria. They are not known to extend into North 

 America; in fact, of the 15 North American species, only two are known to 

 extend into South America. — J. M. C. 



Ripening of tomatoes. — Sando 8 finds that the maturity of a tomato is 

 dependent upon its age and not upon its size in the growing conditions under 

 which he worked. His analyses show that throughout the ripening period 

 there is an increase in moisture, acids, and sugars, and a decrease in solids, 

 total nitrogen, starch, pentosans, crude fiber, and ash. Sugars increase from 



a 



3 Evans, A. W., Notes on New England Hepaticae. XV. Rhodora 21: 149-169. 

 pi. 126. figs. 14. 1919. 



« , Notes on North American Hepaticae. VIII. Bryologist 22:54-73. 



pi. 2. figs. ij. 1919. 



-, A taxonomic study of Dumortiera. Bull.Torr.Bot. Club 46: 167-182. 1919. 



•, A new Riccia from Peru. Torreya 19:85-88. fig. 1. 1919- 



, Three South American species of Asterella. Bull. Torr. Bot. Club 



46:469-480. 1919. 



8 Sando, Chas. E., The process of ripening in the tomato, considered especially 

 from the commercial standpoint. U.S. Dept. Agric, Bull. 859. 1920. 



