Biologie. — Morphologie, Befruchtung, etc. 467 



venia L. und zu der vierten z. B. Malachiutn aquaticuni L. Über die 

 einzelnen Unterschiede muss das Original selbst nachgelesen werden. 



O. Damm. 



Schulz^ A., Beiträge zur Kenntnis des Blühens der einhei- 

 mischen Phanerogamen. 9. Mitteil. (Berichte d. deutsch, bot. 

 Ges. XXIV. p. 372-381. 1906). 



Aus den Beobachtungen des Verf. ergibt sich, dass Arenaria 

 s^erpyllifolia L. und Moehringia trinervis L. zu der zweiten Gruppe 

 der Alsinaceen gehören (s. vor. Referat!). Die einzelnen Phasen der 

 Blütenentwicklung werden eingehend beschrieben. 0. Damm. 



Blatter, E., The 'pectinate organs' of Trapa bispitiosa , Rab. 

 (Water chestnut). (Journal of the Bombay natural Historv 

 Society. Vol. XVII. m 1. p. 84-88. Figs. 1—4. 1906.) 



The pectinate organs of Trapa bispinosa are considered by some 

 to be stipules, whilst others regard them as true leaves or even 

 roots. The lateral processes on these organs are arranged in four 

 Spiral rows, so that the term 'pectinate' is not precise. A Single 

 central bündle extends through the main axis and smaller ones 

 through the lateral processes, the bundles being simpl}^ embedded 

 in parenchyma bounded by an epidermis of elongated cells with 

 extremely thin outer walls and containing chloroplasts ; no stomata 

 are present. On the basis of these observations the author concludes 

 that these urgans represent submerged leaves. F. E. Fritsch. 



Drabble, E., The Transition from Stern to Root in some 

 Palm Seedlings. (New Ph^^tologist. Vol. V. N^. 3. 1906. p. 56—66. 

 with 7 textfigures.) 



In the seedling of Phoenix dactylifera the root contains about 

 twelve xylem groups; on passing upwards the elements of the meta- 

 xylem portions decrease in size and the bundles become more united. 

 Then ground parenchyma appears on the inner side of the protoxylem 

 groups, so that the latter become separated from the metaxylem and 

 ultimately disappear. The fusion of the metaxylem masses results in 

 several centrally placed groups and, at a higher level, protox3iem 

 appears in each in a central position; at a still higher level this 

 becomes endarch. The cotyledonary traces are continuous with the 

 axial X3"lem groups which also give rise to the plumular bundles. 

 During the transition the phloem loses connection with the xylem 

 and runs in Strands in the ground tissue. Some of these Strands pass 

 to the phloem bundles of the stem and some to the x^iem groups of 

 the cotyledonar}' sheath. Where the ground tissue of the sheath is 

 loose the individual bundles are surrounded by a ring of cuticularised 

 cells which is often incomplete on the xylem side. 



Livistona niauritana. Close to the seed the cotyledon stalk contains 

 about fifty bundles but on passing downwards the number is reduced 

 by fusions; the protoxylem is typically endarch. Half way down the 

 stalk nine bundles are found grouped around a few centres to which 

 the protoxylems are directed. The ground tissue contains large air 

 Spaces and the cells immediately external to the bundles possess 



