402 Allgemeines. — Morphologie etc. — Palaeontologie. 



Ziehungen zu den Witterungsverhältnissen Hessen sich mit Sicher- 

 heit nicht nachweisen. Die Angaben widersprechen sich vielfach. 

 Der Schaden ist bis jetzt noch nicht sehr bedeutend, wenigstens 

 nicht so gross wie in Frankreich (im Jahr 1908); nur stellenweise 

 führte die Krankheit zu erheblichen Wachstumsstörungen (Verküm- 

 merung der Johannestriebe und der Knospen). Bemerkenswert ist 

 die Angabe des Verf. dass in 19 Forstämtern das Auftreten des 

 Mehltaus schon früher (auch vor 1907) beobachtet worden sei. (Ob 

 diese „Beobachtungen" zuverlässig sind? d. Ref.). Die Vermutung 

 der Eichenmehltau sei durch Phyllactinia corylea verursacht, hat 

 sich als nicht richtig erwiesen. Sie findet darin ihre Erklärung, dass 

 auf einzelnen eingesandten, mehltaukranken Eichenblättern Phyllac- 

 //;2/(7perithecien beobachtet wurden, welche aber, wie sich dann 

 herausstellte, „angeflogen" waren, oifenbar von benachbarten Hasel- 

 nusssträuchern. Neger (Tharandt). 



Petcb , T., Abnormalities in Hevea brasüiensis. II. Burrsand 

 Nodules. fCirc. Agric. Journ. Roy. Bot. Gard., Ceylon, IV. 15. 

 March 1909.' p. 155—164.) 



The paper deals with two types of excrescences on the stem of 

 Hevea which seriously interfere with tapping. In the first type burrs 

 are produced which are shown to be entirely due to wounds over- 

 grown with new wood and bark. The cambium after Alling up the 

 wounded area retains its activity and forms a canker-like growth 

 or burr. 



The second type described is more widespread and serious. 

 The burrs here are caused by nodules in the cortex as in the case 

 of those of ßeech and Apple. The young nodules appear as cores 

 in the cortex and are separated from the wood and cambium by 

 ordinary laticiferous tissue. Fach core possesses a cambium of its 

 own which forms new wood and bark. With increase in size the 

 core forms on the inner side a conical point which ultimately fuses 

 with the wood of the main stem. Latex cannot be obtained from 

 trees that are badly burred. This type of burr which is regarded as 

 one of the most serious troubles in Hevea cultivation is to some 

 extent a normal feature in Hevea brasüiensis. At the same time the 

 author believes that they are also formed by the use of the pricker, 

 the teeth of which might push fragments of bark into the cortex 

 and thus Start centers of Irritation. A. D. Cotton (Kew). 



Thomson, R. B., The megasporophyll of Saxegothaea and 

 Microcachrys. (Bot. Gaz. XL VII. p. 345—354. pls. 22—25. May 1909.) 



From the occurrence of a Single Inversion in the vascular supply 

 of the cone scale of Saxegothaea and Microcachrys versus the double 

 Inversion in Abieteae, also from the occasional presence of mega- 

 sporangia on the lower surface of the scale, the author concludes 

 that the cone scale in these genera does not represent two leaves 

 of a Short shoot but a Single sporophyll. Thus the micro- and megasporo- 

 phylls are homologous. The generalization is extended to all Taxaceae, 

 which are held to be closely related to the Araucarieae. 



M. A. Chrysler. 



Stopes, M. C, Plant-containing Nodules from Japan, con- 

 sidered structurally in their relation to the 'Coal-Balls' 



