XVI PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



putting imported Orchids into quarantine before introducing them 

 into the Orchid-houses, lest those structures should be overrun 

 with exotic insects. Bisulphide of carbon was recommended as 

 useful for the destruction of insects. Its highly inflammable 

 nature must, however, be borne in mind. 



Mr. Michael, speaking of the presence of Acari in dust- 

 sweepings, alluded to the immunity which these creatures possess 

 against poisonous substances, such as bisulphide of carbon. 

 Desiccation is the only method of killing these creatures, but this 

 cannot always be carried out to a sufficient extent without injuring 

 the plant. 



" Blue" Primroses, dc. — Mr. G. F. Wilson showed various 

 seedling Primroses of a dark slaty-blue colour, and some plum- 

 coloured with a yellow eye. He also showed flowers of a hybrid 

 Narcissus, presumably between N. cyclamineus and N. John- 

 stonei. 



Exfoliated Bark in Pears. — Mr. Jenner Weir showed shield- 

 shaped masses of bark, two or three inches long, one or two 

 inches broad, which became detached from the stem of a Beurre 

 Clairgeau, the wound so formed subsequently healing up by 

 " occlusion " in the ordinary way. 



Camellias, Azaleas, dc., Diseased. — From Christchurch came 

 branches of Camellias, Bhododendrons, and Azaleas gradually 

 shrivelling and dying, more than twenty large plants having died 

 during the last two years without apparent cause. The Camel- 

 lias were badly infested with scale, but nothing could be seen to 

 account for the condition of the other plants. It was suggested 

 that a salt blast might have affected the plants. 



Ivies. — Dr. Masters brought shoots of numerous varieties of 

 Ivy growing on a wall facing the west, to show the very different 

 way in which they, though all belonging to one species, suffered 

 from the effects of frost. In some the leaves were quite killed, in 

 others wholly uninjured, with every intermediate degree of injury. 

 Mr. Jenner Weir pointed out that the variety himalaica was 

 notoriously more tender than many others. Dr. Masters thought 

 it most probable that the whole of the varieties now grown in 

 gardens originated from home-grown plants of Hedera helix. 

 He had himself seen two or three forms growing on the same 

 plant. Hedera helix is noted by Mr. C. B. Clarke, in Hooker's 

 " Flora of British India," ii., page 739 (1879), as growing through- 



