ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 565 



BOTANY. 



GENERAL, 



Including the Anatomy and Physiology of Seed Plants." 



Cytology, 

 including 1 Cell-Contents. 



Nature and Function of the Nucleolus. * — E. Paratore pub- 

 lishes some further researches upon the radical tubercles of the 

 Leguminosse, with regard to the structure and alteration of the nucleus 

 of the tubercular cell iu Yicia Faba. By the use of new reagents he 

 has confirmed his results of last year and has arrived at some new ideas 

 about the nature and function of the nucleolus. He quotes the views of 

 Cavara and of Buscalioni and others, and calls attention to the frequent 

 difficulty of distinguishing nucleoli from macrosomes, to the inconstancy 

 of the reaction of nucleoli and chromatin to differential stains, to the 

 identity of coloration of both in various physiological and pathological 

 conditions, and to the appearance of many granules more or less easily 

 identifiable with the nucleolus. He thinks that the nucleolus may be 

 a hypertrophic and differentiated chromosome, and that it may be a 

 metabolic centre of the nucleus and especially of the chromatin, an 

 element of nutrition and of respiration. 



Cytological Changes accompanying the Secretion of Diastases — 

 J. C. Torrey has studied the place, mode, and time of origin of the 

 diastatic enzyme in seeds of maize and barley. He finds that the enzyme 

 arises in the nuclei of the columnar epithelium of the scutellum, in 

 the form of dark staining granules which exude in small streams through 

 breaks in the membrane and collect at the end of the cell next to the 

 endosperm, where they are ultimately dissolved. Immediately after their 

 disappearance the first signs are observed of the destructive action of 

 a ferment on the cells of the endosperm, and starch-grains soon appear 

 in greater abundance on the cells of the scutellum. The formation of 

 the ferment begins in the nuclei before the commencement of the resting 

 period. The process of secretion is at first intermittent, but after the 

 third day of germination until the final exhaustion of the cells the secre- 

 tion is more continuous. 



Crystals of Calcium Oxalate in Seedlings of Alsike.J— J. Percival 

 describes the distribution and first appearance of crystals of calcium 

 oxalate in Trifolium hybridum in plants grown under various conditions. 

 Plants grown in distilled water in paraffin-lined flasks show development 

 of crystals, first in the petioles of the cotyledons, and then near the tips 

 of the vascular bundles in the primary leaf. They very rarely occur in 

 the hypocotyl or root. Similar development along the track of the vas- 



* Malpighia, xv. (1902) pp. 178-87. 



+ Bull. Torr. Bot. Club, xxix. (1902) pp. 421-35 (1 pi). 



X Journ. Linn. Soc. (Bot.), xxxv. (1902) pp. 396-402 (6 figs.). 



