Band 102. Nr. 22. XXVII. Jahrgang. II. Bd. Nr. 22. 



Botanisches Centralblatt 



Referirendes Organ 



der 



Association Internationale des Botanistes 



für das Gesamtgebiet der Botanik. 



Herausgegeben unter der Leitung 

 des Präsidenten: des Vice-Präsidenten: des Secretärs : 



Prof. Dr. R. v. Wettstein. Prof. Dr. Ch, FSahaisIt. Dr. J. P. Lotsy. 



und der Redactions-Commissions-Mitglieder : 



Prof. Dr. Wm. Trelease und Dr. R. Pampanini. 



von zahlreichen Specialredacteuren in den verschiedenen Ländern. 

 Dr. J. P. Lotsy, Chefredacteur. 



[Vo. 48. 



Abonnement für das halbe Jabr 14 Mark 



durch alle Buchhandlungen und Postanstalten. 



1906. 



Alle ffir die Redaction bestimmten Sendungen sind zu richten an Herrn 

 Dr. J. P. LOTSY, Chefredacteur, Leiden (Holland], Rijn- en Schiekade 113. 



Petrie, D., On the Pollination of the Puriri (Vif ex liicens 

 T. Kirk.) (Transactions of the New Zealand Institute for 1904. 

 Vol. XXXVII. 1905. p. 409-411.) 



The Chief time of flowering of the Puriri is in winter; before 

 the flower-bud opens the corolla has nearly reached its füll size 

 and the flower is horizontal or slightly drooping. The tips of the 

 filaments of the stamens are sharply curved downwards and the already 

 dehiscing anthers are held within the concave infolding of the under 

 lip. After the opening of the flower most of the pollen falls or is 

 brushed away and the stamens then straighten out and lie along the 

 Upper internal surface of the corolla-tube; secretion of nectar slowiy 

 commences. The style at this stage is only half-grown, and lies be- 

 tween the two pairs of filaments, but after two or three days it grows 

 out to its füll length. Flying insects do not frequent the flowers 

 and pollination is effected exciusively by small birds, who in passing 

 from plant to plant cannot avoid bringing pollen from young to old 

 flowers. F. E. Fritsch. 



Pollock, J. B., Variations in the pollen grain of Picea ex- 

 celsa. (Amer. Naturalist. XL. p. 253 -286. April 1906.) 



The number of prothallial cells is found to vary from one to 

 three, though the latter number was found in only 3,8"/o of the pollen 

 grains examined. In the majority of cases only one prothallial cell 

 is present, but in some of these cases the first cell may have dis- 

 appeared, though the writer holds that this is not necessarily the 

 case. The arrangement of the prothallial cells may also vary, since 

 in some cases the cells lie side by side. 2,4''/o of the pollen grains 



Botan. Centralblatt. Band 102. 1906. 37 



