BOTANY. 

 By Prof. Wllliam G. Faelow. 



The greatest activity has been shown this year in the departments of 

 vegetable physiology and anatomy and publications describing new spe- 

 cies of phaenogams and fungi, while comparatively few works have ap- 

 peared relating to algse and higher cryptogams. 



VEGETABLE ANATOMY. 



Strasburger has published two important papers on the structure of 

 the cell. In his Theilungsvorgang der Zellkerne he describes and figures 

 the minute changes which the cell-nucleus undergoes during division, 

 and finally concludes that the division of the cell does not arise prima- 

 rily from the division of the nucleus, but rather that the changes which 

 tend to bring about cell-division are the exciting cause of the division 

 of the nucleus itself. In his second paper, Bau und Wachsthum der Zell- 

 haute, he treats not only of the formation and thickening of the cell- wall, 

 but also of the growth of starch grains, the molecular structure of or- 

 ganized structures, the function of the nucleus, and several other points. 

 Many of the facts which have hitherto been explained by the theory of 

 intussusception Strasburger now believes can be better explained by 

 the apposition theory. He is confirmed in his previous view that the 

 nucleus plays an active part in the formation of j)rotoplasm, since, if we 

 except the sieve-cells, the nucleus is of all the living parts of a cell the 

 most persistent part. Tangl has published a paper on the division of 

 the nucleus and the cell in the formation of the pollen in HemerocalUs 

 fulva, and the Bot. Zeitung has a paper by Zalewski on the division of 

 the nucleus in the mother cells of the pollen in some Liliacece. In the 

 last-named journal is also a paper by Zacharias, in which he gives a de- 

 tailed statement of the opinions of different writers on the chemical 

 nature of the different parts of the nucleus and a critical review of the 

 terminology of the parts of the nucleus. The chemical character of 

 protoplasm has been studied by Loew, Bokoruy, and Eeinke in papers 

 in the Bot. Zeitung and elsewhere, but the complications of the subject 

 can hardly be followed except by persons thoroughly versed in chem- 

 istry. 



Two important papers have appeared from Schwendener — die Schutz- 



scheide und Hire VerstcirJcungen and Scheitelwachsthum der Phanerogamen 



551 



