ABSTRACTS. 



525 



than that required by the more southern-growing sorts, and the proxi- 

 mate cause of its special suitability is thus at once indicated. 



The author remarks that the optimal temperature for ripening the 

 wood is not necessarily identical with that for the development of the 

 V'Cgetative organs. Thus, to quote a specific instance, growth was most 

 pronounced at 18° C, whilst the best tissue-differentiation {i.e. ripening) 

 occurred at 22° C. Possibly, however, the restraining influence of intense 

 light on growth was not sufficiently taken into account here, for the 

 higher temperature involves a more intense insolation. It may well be 

 that, had the intensity of the light been kept constant, the growth would 

 have been more rapid and pronounced at 22° than at 18°. At any rate 

 such considerations may serve to point out the complex nature of the 

 interacting factors even in cases apparently simple. The effects of the 

 rainfall, and especially of its distribution, are also reviewed, and the direct 

 action as affecting the soil and nutrition of the plant is considered, as well 

 as the more indirect result of the diminished light arising from an evenly- 

 distributed rainfall. The latter influence is strikingly illustrated by the 

 meteorological conditions which prevail in the north and south regions of 

 France respectively. 



The effects of subsoil water are shown by its influence on the vines in 

 certain areas around Montpellier, in which, in spite of the generally 

 admirable climate, the vines do not properly ripen on the affected spots. 

 The contour of the land and other local conditions also exert their due 

 influence, and the chemical nature of the soil, especially in connection 

 with manures, is also a matter for consideration. Excessive nitrogenous 

 manuring, as might be expected, encourages rank growth, but is unfavour- 

 able to ripening, whilst phosphates and lime in moderation are used with 

 beneficial effect. Diseases which influence the leaves and other vegetative 

 organs are of course injurious, whilst those {e.g. cases of black-rot) which 

 may be confined to the fruit do not appear to exert any material influence 

 on the process. 



The memoir is illustrated by useful figures and charts which render 

 it easy to appreciate the various points raised by the author in his 

 important contribution to agricultural physiology. — J. B. F. 



FROM CURRENT HORTICULTURAL PERIODICALS. 



{See also imge 199.) 



Acanthacese, African. By Spencer Le M. Moore {Journ. Bat. 

 465, p. 300; 9/ 1901).— Descriptions of the following new species : 

 Thunbergia Elliotii, Blepharis extenuata, B. Scully i, Keuracanthus 

 gracilior, Justicia Taylorii, J. Baumii, and /. Smithii. — G. S. B. 



Acclimatisation, Effect of Last Winter on Various Plants 

 (near Dantzig). By R. Miiller {Gartenflora, p. 402 ; 1 8 1901).— Last 

 winter was more destructive than any of the previous thirty years, 

 apparently on account of (1) the exceptionally mild weather at the end of 

 December, followed immediately by a rapid decrease of the temperature 



