NOTES AND ABSTRACTS. 



289 



Six species of Pleoravenelia, n. gen., are also described in detail, as 

 well as one species of Neoracenelia, n. gen. — G. H. 



Red Currant, An Unfruitful. By Dr. Ewert (Gartenflora, p. 210, 

 figs. 27-32; 15/4/03).— Unfruitful Red Currants which bloom well but 

 set no fruit are occasionally met with. Aitken investigated a case, and 

 could not trace a definite connection of unfruitfulness to want of fertilising 

 constituents in the soil. 



Ewert noticed an example of an unfruitful bush among those which 

 were normal, growing on the same soil, and was led to a study of the 

 biology of the flower. 



It was found that among the different varieties of Red Currants there 

 is a great variation in the length of the style of the flowers, which 

 leads to a physiological dioecism. In the unfruitful specimens the 

 width of the stigma was found much less than among fertile bushes. 



J. P. 



Regeneration, Further Studies in. By R. Goebel (Flora, xcii. 

 1903, pp. 132-146 ; 7 cuts). — (1) Regeneration and new-formation after 

 injury are phenomena which pass into one another. The determining 

 factor has been regarded as the wound- stimulus by Wiesner ; but the 

 facts rather point to the separation as the true stimulus. (2) The 

 chief subjects of experimentation were Bryophyllum, Begonia Bex, 

 Strcptocarpus Wendlandii, and Cyclamen. An interesting parallel is 

 drawn between the regenerative phenomena in Melocactus and in the 

 fungus Stercum hirsutum. The whole paper is full of interest, but 

 not suited to abstracting, as it is full of tersely put detail. — M. H. 



Rhododendron brachycarpum. By Sir J. D. Hooker (Bot. 

 Mag. tab. 7881). — Nat. ord. Ericcce, tribe Bhodorece. Native of Japan. 

 It flowered at Kew in 1902. It is a large, robust shrub, 6-10 ft. high, 

 leaves 4-6 inches long. Flowers in a globose corymb. Corolla large, 

 white, with a faint rose-pink blush in the medial line, reddening towards 

 the tip. [In the plate the corolla is represented as of a pale primrose 

 colour.] — G. H. 



Rubber-producing Plants in Queensland. By Howard Newport 

 (Qu. Agr. Journ. xii. January 1903). — This report is concerned chiefly 

 with Tabernamontana crassa, of which a consignment of 103 small 

 plants was received in 1899, and of these 53 are still living. Some 

 rubber has been obtained from these trees, and submitted to buyers of 

 rubber for report. The opinion obtained is that the rubber is waxy, but 

 if it can be produced expeditiously, and the quality improved by better 

 methods of collection and coagulation, it is likely to prove a valuable in- 

 troduction, as the tree readily adapts itself to conditions of climate, but 

 hitherto the trees are disappointingly small. — M. C. C. 



Rudieularia, a new Genus of Valoniacese. By F. Heydrich 

 (Flora, xcii. 1903, pp. 97-101). — The definition of a newmonotypic genus 

 allied to Apjohnia, but possessing rhizoids ; from the Loo-choo Islands. 

 No cytological details are given. — M. H. 



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