Morphologie, Teratologie, Befruchtung, Cytologie. 595 



Bobisut, O., Ueber den Funktionswechsel der Spaltöff- 

 nungen in der Gleitzone der Nepenth es- Kannen. (Anz. kais. 

 Akad. Wiss. Wien. IV. p. 23. 1910.) 



Die in der Gleitzone auftretenden halbmondförmigen Zellen 

 sind, wie schon Haberlandt nachgewiesen hat, sonderbar meta- 

 morphosierte Spaltöffnungsapparate. Sie stellen Einrichtungen vor, 

 die zwar ein Herabkriechen, nicht aber ein Hinauf kriechen und 

 Entfliehen der zu fangenden Insekten ermöglichen. 



Matouschek (Wien). 



Costerus, J. C. and J. J. Smith. Studies in tropical terato- 

 logy communicated by J. C. Costerus. (Ann. Jard. bot. 

 Buitenzorg. XXIII. 1. p. 1 — 19.) 



The material is studied in Java by Dr. Smith in the fresh 

 State, by Costerus dried or immersed in alcohol. The most interes- 

 ting monstrosities are those of the Orchidaceae. The characteristics 

 of the family: re version, condensation and suppression of organs 

 are the chief causes i. e. they affect in the following species such 

 parts as in ordinary circumstances remain unaltered , for instance 

 sepals cohering, sepals grown together with petals, petals coalescing 

 with the labellum or suppression of the labellum {Dendrobium spec, 

 Pogonia discolor Bi., Rhynchostylis retusa Bl. Paphiopedilum spec.) 



Abnormal spadices: Alocasia macrorhisa, Anthurium spec, Zea 

 Mays. Abnormal inflorescences: Mnsa sapientium, Acalypha hispida, 

 Biiibophyllum obscurum J. J. S. Abnormal flowers: Gloriosa Planta 

 Loud. (apostasis and augmentation) Telanthera philoxeroides Miq. 

 (stamens changing into pistils) Caesalpinia pulcherrima Sw. (apostasis, 

 median and lateral prolefication). Abnormal leaves: Caladium, Colo- 

 casia affinis, Carlndovica palmata R. et P., Hevea brasiliensis Muell. 

 Arg., Begonia Rex Ptz., Adiantum spec. Th. Weevers. 



Davis, B. M., Cytological Studies on Oenothera. I. Pollen 

 Development of Oenothera grandiflora. (Ann. of Bot. XCII. p. 

 551-571. PI. XLI— XLII. 1909.) 



The study of the cytology of the Oenotheras has suggested itself 

 to several authors, owing to the intimate relation of these plants 

 to the mutation theory of De Vries. These authors have approa- 

 ched the problem through Oenothera Lamarckiana or some of its 

 derivatives. They have thus dealt with forms of recent or uncertain 

 origin. The present author, however, investigates the cytolog}*- of 

 Oenothera grandiflora, Ait, a characteristic and well-established 

 native American species. 



The most interesting of the author's observations deal with the 

 formation of the bivalent chromosomes. The chromatic material 

 emerges from Synopsis by a general loosening up of the elements 

 which compose the contracted knot, and then, for the first time, it 

 becomes evident that the chromatin has taken the form of a group 

 of rings. Later the rings may be easily counted, the number being 

 seven, which is half the number of chromosomes present in the 

 sporophytic mitoses. These become the seven bivalent chromosomes 

 characteristic of the heterotype mitosis. In some preparations it 

 seems clear that the rings have originated from chromatin loops 

 which extended from the synaptic knot. Also when groups of chro- 

 mosomes are viewed in favourable positions two, three, or more 



