xvi 



PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



SCIENTIFIC COMMITTEE. 



February 14, 1893. 



Prof. M. Foster, Sec. E.S., in the Chair, and nine 

 members present. 



Soil with Mites, &c. — Mr. Michael reported upon a sample of 

 earth sent from Jura Forest, and found that it contained wire- 

 worms, some Thysanurida*, and mites (Gamasida?). The mites 

 were in this case not injurious to plant life, but rather " friends," 

 as they were predatory on other animals. In another sample 

 sent there were Thysanuridae and wireworms, but no mites. The 

 soil being in a bad condition, should be treated with gas-lime, 

 or other usual remedies for wireworm. Mr. McLachlan observed 

 cn the importance of such investigations as the present, as 

 they revealed what creatures were " friends " to the cultivator, 

 such being very often regarded unwittingly as " foes." 



Parsnip devoured by a Vole. — Dr. Masters exhibited a 

 specimen from Bagshot, in which the whole of the interior had 

 been consumed, nothing but a thin shell of cortex being left. 

 He also showed a drawing of a monstrous Turnip which had 

 grown not unlike a Mandrake in form. 



Burr Knot on Apple Boots.— Dy. Masters also showed a 

 specimen from a "Burr Knot" Apple-tree, a feature charac- 

 teristic of certain varieties of Apples, such being used for 

 propagating purposes. It was referred to Prof. Farmer for 

 examination. 



Fog Report. — Prof. Oliver presented the second report on his 

 investigations upon M The Effects of Urban Fog on Cultivated 

 Plants," which was ordered to be printed for discussion at 

 the next meeting. The following is a brief abstract : 14 The 

 report deals especially with the physiological aspect of the ques- 

 tion, matters of more purely local interest being reserved for a 

 forthcoming communication. The observed action of fog upon 

 plants is described in detail, and the share taken in this action 

 by the reduction of light on the one hand, and by atmospheric 

 impurities on the other, is critically discussed in the light of the 

 writer's experimental results. The position taken up by the 

 author is that 1 fog ' is, physiologically speaking, a much more 

 complex affair than has been suspected. In presenting his 



