Morphologie elc. — Varietäten etc. 565 



teils durch Insekten zustande; ausserdem dürfte Selbstbestäubung 

 vorkommen: die Antheren berühren öfters die Narben während der 

 Anthese. Die Frucht reift unter Wasser, löst sich (wie bei dem von 

 Wettstein untersuchten A. Gtiillotii) von der Achse und berstet. 

 Die Form ist oft vivipar. Grevillius (Kempen a. Rh.). 



Me Allister, F., Nuclear Divison in Tetraspora lubrica. (Ann. 

 Bot. XXVII. p. 681—696. 1 pl. 1913.) 



The paper opens with a brief summary of the existing literature 

 dealing with nuclear division in the protozoa and green algae. 



An account is then given of nuclear division in Tetraspora 

 lubrica which grows as gelatinous colonies in shallow, running water 

 in the neighbourhood of Ithaca, N. V. The author regards the 

 Tetrasporaceae nearly allied to the Chlamydonionadaceae The main 

 points brought out in his investigation are as follows: 



The nucleus in the resting condition has a chromatic reticulum, 

 net knots and nucleole distributed in the same manner as in the 

 higher plants. A definite spireme is formed from the reticulum. The 

 spireme Segments to form about thirteen chromosomes. The nucleole 

 shows no signs of disintegration until the increase in chromatic ma- 

 terial has come to an end. Centrosomes are not to be identified at 

 any stage of the nuclear division. Cell-division is accomplished by 

 the Splitting of a granulär cell-plate which has been formed by the 

 central spindle. The Splitting takes place from the centre outward. 

 The entire pyrenoid Segments to form several starch bodies. No 

 differentiated central area is present. 



In the discussion which concludes the paper, the author draws 

 attention to the striking uniformity existing throughout the green 

 plants on the phenomena of nuclear division, and points out that 

 the Euglena type of mitosis has not been reported for any green 

 plant. He is thus led to the view that the origin of the Chlamydo- 

 monadaceae from the Euglenidae, as suggested by Blackman & 

 others, must be rejected. Agnes Arber (Cambridge). 



Davis, B. M., Genetical studies on Oenothera III. Further 

 h3^brids of Oenothera hiennis and O. grandißora that resemble 

 O. Lamarckiana. (Amer. Nat. XLVI. p. 377—427. July 1212.) 



The writer maintains his earlier contention that O. Lamarckiana 

 has arisen as a hybrid between types of O. hiennis, and O. grandi- 

 flora, and that a hybrid taxonomically similar to O. Lamarckiana 

 can now be synthesized. In the 1911 cultures designed to test this 

 hypothesis, a different biotype 0. hiennis was used in hybridizing 

 with 0. grandißora. resulting in the production of plants more clo- 

 sely resembling O. Lamarckiana than did those of previous years. 

 F2 plants from earlier crosses show many variations of progressive 

 and of retrogressive nature, some apparently of the rank of new 

 species. The evidence against the existence of native American spe- 

 cimens of O. Lamarckiana is strengthened by consideration of a 

 certain sheet in the Gray Herbarium. M. A. Chrysler. 



Erikson, J., Rönnoxeln (Sorbits aucuparia X suecica). (Fauna och 

 Flora, p. 136-139. 3 Textfig. Uppsala 1913.) 



Der vom Verf. auf Vämö in Bleking, Südschweden, ent- 



