18 Biologie. — Morphologie etc. 



sich schon an das Helle gewöhnt haben, nicht nur mit solchen, die 

 eben erst den Stock verlassen. Vom Standpunkte des Biologen aus 

 ist jedenfalls die seit Sprengel durch so viele Beobachtungen 

 gestutzte Ansicht vom Farbensehen der Bienen durchaus noch nicht 

 beiseite zu legen. H. Klenke (Braunschweig). 



Bremer, G., Reliquiae Treubianae. IL The development 

 of the ovule and embryosac of Pittosporuni ramißorum 

 Zoll, and Pittosponan tUnorense Blume. (Ann. Jard. bot. Bui- 

 tenzorg. 2^^ Serie. XIV. p. 161 — 164. 1916.) 



Two species of Pittosponim were examined by Miss Bremer: 

 P. ramiflormn and P. thnorense\ the materials were collected by 

 Prof. Treub and Dr. Kuyper at Buitenzorg. There is a great 

 difference in development of ovule and embryosac between these 

 two species. 



From the normal type deviating details have been observed: 



In both species the nucellus degenerates and in the fullgrown 

 embryosac the nucellus has been destroyed. 



With P. rarnifloruni the cells of the tetrad lie in a row, the 

 second cell from below being the biggest one and still present when 

 the other cells are already degenerating, It is probable therefore 

 that this cell develops into the embryosac. In many cases of this 

 Stadium the integument had grown over the nucellus. The further 

 development of the embryosac is pretty normal. 



The shape of the tetrad of P. tiinorense deviates very much 

 from the ordinary type, the four tetradcells lying in two rows, 

 each of two cells. Sometimes the tetradcells are distributed a little 

 less regularly, but they are never lying exactly in a row. Evidentl}'- 

 one of the bottomcells develops into an embryosac, which in a 

 normal wa3^ will become eight nucleate. The antipodes donot de- 

 generate. 



This research shows clearly that it would be dangerous to base 

 a comparison between Pittosporaceae and other Rosales upon the 

 structure of the embryosac because in this respect there is a great 

 difference between the two species of Pittosponim. examined. 



M. J. Sirks (Bunnik). 



Costerus, J. C, A fresh investigation into the structure 

 of the flower of Canna. (Ann. Jard. bot. Buitenzorg. 2'^e Serie. 

 XIV. p. 165-184. 1916.) 



The paper brings the outcome of the authors own investigations 

 upon normal and teratological flowers of Camia. The researches were 

 facilitated by the circumstance, that a great many new varieties 

 which surpassed the original species in size and brought disappe- 

 aring characters back to a greater distinctness, have been cultiva- 

 ted, in the chief place by the wellknown French grower Crozy. 



The points in the morphology of C<7;/»«flowers, which have as 

 yet been left undecided, have reference to: 



1°. The morphological value of the staminodes separately; 



2^. The morphological value of the anther; 



30. The morphological value of the style and the reason for its 

 contorted base and excentric position. 



The writers descriptions and considerations cannot be reviewed 

 in a more compressed form, than they are given in the original 

 paper. M. J. Sirks (Bunnik). 



