564 JOUKXAL OF THE KOYAL HORTICULTURAL SOCIETY. 



March and beginning of April ; on very sunny days the pots in which 

 they are set are phmged in water. When rooted each plant is placed in a 

 separate small pot, in soil similar to that used for Chrysanthemums, and 

 the pots placed in a cool greenhouse and covered with glass until the 

 plants ha^e become established, after which they are exposed to the air. 

 In May and June, when the pots have become encircled by the roots, the 

 plants are placed in the open ground, preferably on a rainy or cloudy day. 

 During the second half of August they should be taken up and placed in 

 pots of 20 or 25 cm., which should be plunged in soil in the open and 

 fully exposed to the sun ; it is needful to give them abundance of water 

 three or four times a day. In September, when new roots have been 

 emitted, one or two applications of liquid manure will stimulate their 

 growth. Before frost sets in the plants are to be removed into a 

 moderately warm house, and watered during the winter once or twice with 

 liquid manure. They will flower in January or February. A temperature 

 of 10° C. should not be exceeded.— T7. C. li . 



Nelumbium. By Alph. de Vreeze {Rcr. Hort. Beige, t. xxvii. 

 p. 110, Mo. 7, July 1901). — A short article on the distribution, history ,^ 

 and culture of this genus. — G. H. 



Nelumbium speciosum album plenum (Shiroman) {Gard. p. 158, 

 7/9/1901; fig.). — Describing characteristics and colour of this variety; 

 also N. s. roseum plenum, as shown at the Royal Horticultural Society's 

 meeting by Mr. Hudson, from Gunnorsbury House Gardens. — H. J. C. 



Nematodes as Enemies of Horticulture. By Dr. Adolf Oster- 



walder (Gartenflora, p. 337 ; 1 coloured plate and fig. 51 ; 1/7/1901) — 

 The chief nematode plant parasites belong to the genera Tylcnchus, 

 Aphelcnclius, and Heterodera. Representatives of the two former cause 

 diseases of the leaves of Gloxinias, Begonias, Chrysanthemums, Calceo- 

 larias, Saintpanlia ionanthc, various species of Ferns, and injure the 

 stems of Aucnba japonica. They also do considerable damage by 

 attacking the callus or healing tissue at the base of Chrysanthemum 

 cuttings. The leaves of the plants first become spotted on the under 

 surface ; then the upper surface shows yellowish spots which die and 

 turn brown, the whole leaf being ultimately destroyed. The eelworms 

 live in the spongy parenchyma of the leaf and destroy it. The species 

 Heterodera radicicola attacks and produces galls upon the roots of 

 Cyclamen persicnm. Begonias, and occasionally on vine roots. No cure 

 for an infected plant is known ; the only means to reduce the attacks of 

 these parasites is to endeavour to prevent them from gaining an entrance 

 into the soil and pots used for the growth of these plants. Diseased 

 plants should not be thrown on compost heaps, and infected leaves should 

 be picked ofi' the plants and burnt as soon as the trouble is noticed. 

 Sterilising the potting soil by heat, or the application of boiling water, is 

 recommended, and pots which have contained diseased plants should be 

 disinfected by means of boiling water before being used again. Care 

 should be taken to i^revent the introduction of diseased stock into the 

 houses (see also " Worms "). — /. P. 



