168 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



topogon spp.) is a gnat which will bite and suck the blood of any 

 exposed part of the body, and is very troublesome to man and 

 domestic animals during or just before rainy weather in parts of 

 Virginia, particularly in the Blue Eidge Mountains near Beaumont. 



The adult is a minute fly 1 mm. in length, dark grey in colour, 

 with mottled wings. 



The larvae are found on living trees in holes containing dirty 

 water.— y. G. J. 



Radish, Japanese-Daikon. By E. de Noter (Rev. Hort. Beige, 

 p. 136, May 1, 1911). — Increased culture of the daikon or Japanese 

 radish is strongly urged. It produces enormous crops, is easily 

 cultivated, requires light soil, forms an agreeable and nourishing 

 food for man, cooked, and is much relished by cattle. In Japan the 

 daikon is much appreciated, and its cultivation is said to replace corn- 

 growing in many places. In gardens the crop has the advantage of 

 occupying the ground only for a very short time. 



Eight varieties were recently exhibited by the writer at a show 

 in Paris — * Sahura-Jima,* *Ni-Nengu,' 'Mia-Shige,' Ku-Nichi,' 

 *Ki-Nashi,' ' Tokuri,' 'Kameido,' and ' Maru-Jiri. — M. L. H. 



Raspberry (Bev. Hort. de VAlgirie, p. 115, April 1911). — A 

 hybrid, between Buhus Idaeus and B. vitifolius, seen in an Algerian 

 garden is described as hardy, vigorous, and remarkable for the quantity 

 of delicious fruit it bore all the summer. — M. L. H. 



Rats, Poison for {Bev. Hort. de VAlg^rie, p. 254, July 1911).— 

 The bulb of the Scilla maritima is said to be poisonous to rats, though 

 harmless to domestic animals. The bulb must be chopped up and 

 mixed with meat, or made into a paste in the proportion of two-thirds 

 cheese and one-third powdered Scilla bulb. — M. L. H. 



Rehmannia x kewensis. By W. W. (Gard Chron. p. 268, 

 April 6, 1912; with fig.).— Eaised in 1910 by Mr. Coutts, B. Henryi 

 X B. ghitinosa, described as a good decorative plant. — E. A. B. 



Respiration of higher plants, Some further investigations 

 upon the effect of temperature upon. By Dr. J. Kuijper (A7in. 

 Jard. Bot. BuH. ser. ii. vol. ix. pt. i. pp. 45-54 ; 1911 ; with two plates). 

 This is a continuation of the author's previous work upon this 

 subject. His former work had been carried out upon plants growing 

 in the temperate climate of Europe, whilst the present research is 

 upon the vegetation developed under the tropical conditions of 

 Buitenzorg. He used seedlings of Arachis hypogaea and Oryza sativa 

 for this research, and found that these behaved quite like the plants 

 which he had studied in Europe. The two most important conclusions 

 which he draws from his investigations are: — 



(1) The effects of temperature upon the tropical plants examined 

 is the same as upon the plants of temperate climates. The critical 

 temperatiire is, however, 5° to 10° 0. higher for the tropical plants 

 iliaii for those of Europe. Tliis corresponds to tlie fact that the tern- 



