SCIENTIFIC COMMITTEE, MARCH 20. 



Ixv 



of the plant in abundant light would cause growth to proceed in a proper 

 and healthy manner. 



Beetle Grubs in Elm Bark. — Lieut.-Col. Eogers sent elm bark bored 

 by the grubs of a beetle, which Mr. G. S. Saunders took to examine 

 further. See below, March 20. 



Hardy Eucalyptus. — Messrs. Treseder k Co., of Truro, sent branches 

 of a Eucalyptus from their nursery, an introduction from Australia, which 

 they say has stood twenty degrees of frost without injury. Some account 

 of the tree is given in Gardeiiers' Chronicle (July 1, 1905, p. 3), with a 

 figure of the young state, which is somewhat like that of E. cordata. 

 Messrs. Treseder have given the name Eucalyptus Beauchampiana to 

 this form, but it is probably referable to E. cinerea, F. v. Muell. See 

 Bentham, "Flora Australiensis," " iii. 239 [E. pulverulenta is closely 

 allied, if not identical]. In the mature state the leaves are linear- 

 lanceolate, of a glaucous-green with a reddish tinge, and about 3 inches 

 long. 



Soil uncongenial. — A sample of soil with roots of plants quite dead 

 or dying was received. On using the soil a second time after rest it was 

 found that the roots of cucumbers, melons, violets, tomatoes, Koman 

 hyacinths, &c. were quite destroyed. Mr. Chittenden said he had tested 

 the soil, and found that it contained abundance of lime, so that the death 

 of the roots could not be put down to soil acidity. Mr. Douglas, V.M.H., 

 pointed out that there were pieces of clinker and cinder in the soil, and 

 the presence of these suggested sulphur as a possible cause of injury. 



Cultures of Nodule Bacteria. — Mr. Chittenden said that experiments 

 had been carried out in Essex during the past year with cultures of 

 nodule bacteria from America and Germany on beans, peas, lucerne, 

 clover, &c., but in every case without yielding any increase in crop, either 

 in pot cultures or in the field, in spite of the fact that in every case the 

 cultures were proved by means of control cultures to be alive and 

 capable of vigorous growth. Dr. Somerville said that this had been 

 the experience throughout the country, just as it had with " nitragin " 

 a few years ago. 



Scientific Committee, Makch 20, 1906. 



Dr. M. T. Masteks, F.R.S., in the Chair, and some fifty members 

 and visitors present. 



Beetle in Elm Bark. — Mr. G. S. Saunders, F.L.S., reported that the 

 piece of elm bark sent by Lieut.- Colonel Rogers from Sevenoaks was 

 " attacked by the grubs of the elm bark beetle, Scolytus destructor. 

 This pest is a very difficult one to destroy, as the grubs live in positions 

 in the bark in which it is impossible to make any insecticide reach them. 

 About sixty years ago some elm trees in Regent's Park were very badly 

 attacked by this insect, but they were saved by paring off the bark until 

 the grubs were exposed, when the trees were dressed with a mixture of 

 lime and cowdung ; the grubs being exposed to the weather would have 

 died even if the trees had not been dressed. The trees made a good 

 recovery. I cannot suggest any other means for killing the grubs. It is 

 an open question whether these grubs ever injure really healthy trees, for 



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