Cytologie. — Descendenz u. Hybriden. — Morphologie. 661 



Intravital gefärbte Amöben (Amoebu proteus) entfärben sich 

 bekanntlich, wenn sie aus der Farbstofflösung in reines Wasser 

 übertragen werden. Kernlose Theilstücke von Amöben ent- 

 färben sich dabei nur langsamer als kernhaltige: „Bei den kern- 

 haltigen Theilen wirkt die plasmabildende Thätigkeit be- 

 schleunigend auf die Entfärbung, da sie dem Färbemittel die 

 Stoffe entzieht, an die dasselbe gebunden ist; bei den kernlosen 

 Theilen dagegen, in denen ja keine plasmabildende Thätigkeit 

 mehr vorhanden ist, muss in Folge dessen das gänzliche Ent- 

 färben später eintreten." — Aehnlich wie kernlose Theilstücke 

 verhalten sich hungernde Amöben. 



Die übrigen Resultate des Verf. sind vorwiegend für den 

 Zoologen von Interesse. Küster. 



White, CA., The saltatatory origin of species. (Bulletin 

 of the Torrey Botanical Club. XXIX. 1902. p. 511—522.) 



A description is given of a new form of Lycopersicum 

 esculentum from cultures of the Acme variety of this plant, 

 which the author concludes to be a new species originating by 

 mutation. A general discussion of the theory of origin of 

 species as put forward by de Vries is given, and its bearing 

 upon currently accepted ideas of natural selection is examined. 



Mac Dougal. 



Baker, R. T. and Smith, Henry G., On the relation be- 

 tween leaf venation and the presence of certain 

 chemical constituents in the Oils of the E u - 

 calypts. (Journ. Roy. Soc. New South Wales. XXXV. 1901. 

 p. 116—123. With plate.) 



The authors have observed a marked agreement between the 

 chemical constituents occurring in the oils and the venation of 

 the mature lanceolate leaves of the several species, thus forming 

 the genus into several well-marked groups. The „Angophora"- 

 type of venation is fotind to conicide with the presence of 

 „Pinene". Groups of species yielding „Eucalyptol" and „phel- 

 landrene" respectively are also characterised by distinct types 

 of leaf-venation. A group containing „Pinene" and Eucalyptol 

 shews a type of leaf-venation in some respects intermediate 

 between those of the „Pinene" and Eucalyptol" groups. 



H. H. W. Pearson. 



Britton, E. G. and Taylor, A., The Life-history of 

 Vittaria lineata. (Mem. Torrey Bot. Club. Vol. VIII. 1902. 

 No. 3. p. 185—211. pl. 23—31.) 



A füll discussion is given of the literature bearing on the 



genus Vittaria. Both gametophyte and sporophyte are treated. 



„The gametophyte in V. lineata is an irregularly branched, 



pseudo-dioicous prothallium, bearing the archegonia, and giving 



