234 JOVIiNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



fungus— the spores germinate in October— gains access to the interior of 

 the stem, ramifying principally near the cambium. It has not yet been 

 determined whether the fungus enters the stem through the cuticle, or 

 whether it makes its way through a slight wound, nor is it known 

 whether the mycelium is perennial in the tissues. Experimental 

 inoculations were carried out with pure cultures of the fungus. Spraying 

 with Bordeaux mixture or with ammoniacal copper carbonate immedi- 

 ately after the autumn rains commence and again after the leaves fall is 

 recommended, the former solution being used only when there is no fruit 

 on the tree. — F. J. C. 



Aquatic Plants. P>y M. Lagrange (Rev. Hort. Beige, xxviii. No. G, 

 p. 187). — This article deals with the culture of Nymphreas and Nclum- 

 hium. — G. II. 



Asclepiadaceae, A Morphological Study. By T. C. Frye (Boi. 

 Gaz. xxxiv. No. 6, p. 389 ; 3 plates). — The author refers to a previous 

 paper for details on the development of the pollen (Bot. Gaz. xxxii. p. 

 325, pi. 13, 1901), and discusses the development of the stamen and 

 other parts. He first calls attention to almond-shaped glands between 

 the rays of the umbel and at the base of the sepals. They do not secrete 

 honey, and no evidence of any function was discovered. 



The stamens and petals of the plants studied (viz. eight species of 

 pias and two of Acerates) arise from a common ring. The whole 

 stamen in its older stages shows a remarkable tendency to form inter- 

 cellular spaces, the tissue resembling the spongy parenchyma of a leaf. 



After giving a full account of the development of the stamen with its 

 "hood" and "horn," the use of which for pollination is not clear, the 

 author describes the generative cell of the pollen -grain and the process 

 of division. Then follows a full description, with figures, of the formation 

 of the pistil, embryo-sac, and ovule. The papillose surface on the summit 

 is regarded as an abortive stigma (comparable to that in Apocynacece), 

 the stigmatic surface being now transferred to positions below the head. 



G.H. 



Asparagus Sprengeri and A. Duchesnei. By Ch. Pynaert 

 (Bev. Hort. Beige, xxviii. No. 3, p. GO; coloured plate of the second 

 species). — This latter was received from the Congo. It has longer 

 I 'nineties and is a better decorative plant than the former, which it some- 

 what resembles. — G. H. 



Astilbe Davidii. By Sir J. ]). Hooker (Bot. Mag. tab, 7880).— Nat. 

 Old. Saxifragacea, tribe Saxifragece. Native of China &c. The stem 

 ha>- an inflorescence 1 6 ft. high, with a brown, tomentose rachis. The 

 branches, numerous, spiciform, 4-5 ins. long, of dense globose panicles 

 of minute, rose-pink, sessile flowers. — G, II. 



Aubrietias, Some New (Garden, No. 1G44, p. 343; 23/5/03).— 

 \ubrietias are so important in the spring garden and early rock garden 

 ,,,:it il is ;l to have the good new varieties that have lately been 

 i. These seem to divide themselves into two classes: namely, these 



