338 Biologie. — Cytologie u. Befruchtung. 



Marcello , LeOPOLDO , Sopra alcuni alberi longevi di 

 Cava dei Tirreni. (Bollettino della Societä dei Naturalist! 

 di Napoli. Vol. XVI. p. 148 — 150.) 



L'auteur decrit trois exemplaires de Qiiercus Hex et deux 

 de Tilia eiiropaea, qui remontent ä une tres-grande antiquite. 

 Un des Q. Hex a 24 metres de hauteur et la tige a une cir- 

 conference de m. 8,37; l'autre ä 15 in. de hauteur et la tige 

 une circonf^rence de 5,35 m.; le troisieme a 13 m. de hauteur, 

 et la tige une circonference de 5,30 m. Des deux tilleuls. Tun 

 a une hauteur de 16,35 m. et la circonference de la tige 4,43 m., 

 l'autre une hauteur de 30 m. et une circonference de tige de 

 4,50 m.. Ce dernier et le premier Q. Hex peuvent compter 

 plus de mille annees d'existence. A. Terracciano. 



Chamberlain, Charles J., M i t o s i s in Pellia. (Botanical Gazette. 

 Vol. XXXVl. July 1903. p. 28—51. Pls. 12—15. Publi- 

 shed concurrently in Decennial Pubiications of the University 

 of Chicago. Vol. X. p. 327—345. 1903.) 



This paper deals chiefly with the centrosphere, aster and 

 spindle in the first three divisions of the germinating spore of 

 Pellia epiphylla, Conocephaliis, Marchantia, Aneiira, Palla- 

 vicinla, Scapania, Lophocolea and Porella were studied inci- 

 dentally. 



No quadripolar spindles as described by Farmer for 

 Pallavicinla were found in any of the forms studied. 



In the first division of the germinating spore a zone imme- 

 diately surrounding the nucleus becomes comparatively free 

 from starch grains and other coarse granules. It is suggested 

 that some substance escaping from the nucleus causes this 

 zone and stimulates the formation of the extra-nuclear portions 

 of the achromatic figure. He thinks it not impossible that 

 this escaping substance may take the form of a centro- 

 sphere. After the spirem has segmented a pair of dome-shaped 

 Caps appear at opposite poles of the nucleus. Later the caps 

 become resolved into fibers, and the poles may vary from 

 sharply pointed figures to broad indefinite ones. Spindles with 

 three or more poles are common. They are either formed 

 through the influence of three or more centrospheres, or are 

 preceded by the bipolar condition, and never originate iike the 

 multipolar spindles in mother cells of vascular plants. 



The radiations are conspicuous until the spindle has 

 reached its füll length, when they rapidly disappear. When 

 the metaphase is reached the radiations have in general dis- 

 appeared. During the anaphases there is seldom a trace of the 

 radiations, but in the telophase they again appear but are not 

 centered at any single point. This appearance and almost 

 immediate disappearance occurs as the nuclear membrane 

 forms. The radiations are most prominent while the nucleus 

 is elongating, and many radiations connect the poles with the 



