﻿BOTANICAL GAZETTE 



These formulae will also serve to give an idea of the constitution of the 

 anthocyanidins. The fiavonols and flavones are well known yellow pigments of 

 plants. Our thorough knowledge of the chemistry of these pigments is partly 

 due to their extensive use in the dyeing industry. Wheldale 16 has suggested 

 that anthocyanins originate from the flavonol glucosidic pigments by a process 

 of hydrolysis followed by oxidation, and she questions Everest's ideas as set 

 forth above, so far as they apply to the origin of anthocyanins in plants, since 

 the drastic reagents used by Everest are not available for the plant. It would 

 seem that her protest is rather poorly grounded. 



Almost every point established concerning the anthocyanins is of great 

 immediate significance to plant breeders and physiologists. WlXLSTATTER 

 and his students have done much to put our knowledge of this group of pigments 

 on solid foundations, as they previously did for the pigments of the chloro- 

 plast. — Wm. Crocker. 



Anatomy of Isoetes.— Lang/ 7 in continuing his studies of Isoetes, has 

 analyzed the stele of /. lacustris, with the help of apical development. The 



tions due to the occurrence of crowded leaves upon a very slightly elongating 

 axis, accompanied by the continued growth of the cortex. The summary of 

 the analysis is as follows, proceeding from within outward: (i) central colnmn 

 of primary xylem (the strictly cauline region of the stem) ; (2) peripheral zone 

 of xylem, consisting of bases of leaf traces connected with the central cylinder 

 and radially arranged xylem between the entering leaf traces; (3) parenchy- 

 matous xylem sheath, continuous with similar region in leaf trace; (4) primary 

 phloem, continuous with phloem of leaf trace; (5) secondary prismatic tissue, 

 consisting of tracheids, sieve tubes, or parenchyma; (6) meristen of secondary 

 prismatic tissue; (7) cortical tissue. Lang states that such an analysis of the 

 stele of Isoetes " not only affords points for comparison with the Lepidodendreae, 



phology."— J. M. ('. 



Espeletia .— This is a genus of the Asteraceae, restricted so far as known 

 to the high cordilleras of Colombia and Venezuela. The genus is among the 

 most conspicuous of the composites, the leaves and inflorescences^ in most 

 of the species being closely invested by long wool. The genus has just been 

 revised by Standley, 18 who recognizes 17 species, 6 of which are described 

 as new.— J. M. C. 



'"Jour. Genetics 4:369-376. 1915- 

 Lang, William H., Studies in the morphology of Isoetes. II. The analysis 

 of the stele of the shoot of Isoetes la* u tiris in the light of mature structure and apical 

 development. Mem. and Proc. Manchester Lit. and Phil. Soc. 59:29-56- P ls - 4- 

 figs. 7. 1015. 



«» Standley, Paul C, The genus Espeletia. Amer. Jour. Bot. 2 : 468-485- fii 5 - °- 



