NOTES AND ABSTRACTS. 



141 



Dahlias, Sexual Reproduction of. By Professor I?. Gerard 

 (Lc Jardin, vol. xxi. No. 479, p. 42, ; with 3 figs. ; February 5, 1907. 

 Also summary and more practical details on p. 46). — A minute scientific 

 description of the structure of the dahlia flower, and mechanism of 

 pollination, with the intention of assisting practical experiment.— F. A. W. 



Davidia Involucrata. By S. Mottet (Lc Jardin, vol. xx. 

 No. 466, p. 216 ; with 3 figs. ; July 20, 1906).— Gives the history of 

 the discovery of this remarkable tree, with full botanical description. 



F. A. W. 



Deutzia SCabra Thunb., not Hort. By S. Mottet (Le Jardin, 

 vol. xx. No. 464, p. 180 ; with fig. ; June 20, 1906).— The characteristics 

 of the true Deutzia scabra vs. D. crenata, with which it is often confused, 

 are enumerated, with a list of other new species, notably the hybrids of 

 M, Lemoine.— F. A. W. 



Deutzia Wilsoni. By T. F. Duthie (Bot. Mag. tab. 8083).— Western 

 China. Nat. ord. Saocifragaceae ; tribe Hydrangeae. A handsome shrub. 

 Branches reddish-brown ; leaves 3-4^ inches long ; flowers j; inch across, 

 pure white. — G. H. 



"Droppers" of Tulipa and Erythronium, The. By Agnes 

 Robinson (Ann. Bot. vol. xx. p. 429-440 ; 2 plates ; October 1906).— 

 It is pointed out that the vegetative reproduction characteristic cf 

 bulbous plants possesses a great drawback in that it tends to over- 

 crowding. Various methods are adopted by plants to overcome this 

 disadvantage ; these have been classed together as " lateral migration 

 movements." Similarly when the depth in the soil does not appear to 

 be appropriate to the plant, an effort is made to rectify the defect, and 

 for " descending movements" the peculiar stolons known as " droppers " 

 are particularly well adapted. The authoress deals with the subject 

 from an anatomical as well as a morphological standpoint. It is shown 

 that, in the plants mentioned in the title, the immature bulb produces 

 each year a single foliage leaf continued at its base into a hollow tube 

 H the dropper," enclosing a bulb at its tip. The anatomy confirms the 

 view that the dropper is partly axial and partly fcliar ; the region of 

 greatest growth is, however, immediately behind the apex, showing that 

 this foliar-axial organ has become root-like in more than mere 

 externals. — A. D. C. 



Eichornea crassipes, Wintering* of. By E. Courtois (Rev. Hort., 

 November 16, 1906, pp. 525, 526).— Difficult to preserve in winter in water 

 unless the temperature is maintained ; but if the stolons be potted in well- 

 drained sandy peat at end of October, kept in a warm house for a short 

 time, and then transferred to a cool one (under or on the staging with 

 geranium cuttings), they will start into healthy growth the following 

 May when replaced in water, flowering even in the open. — C. T. D. 



Elm Leaf Beetle. By W. E. Britton (U.S.A. Exp. Stn. Conn.; 

 Bull, 155 ; 6 figs. ; May 1907).— The English Elm (Ulmus campeslris) is 



