EXTRACTS OF PROCEEDINGS. 



cxxiii 



point, the gist of which was that some trees suffered less from having 

 their trunks banked-up with earth than might have been anticipated. 

 Some trees in the Eu3ton Road were mentioned in illustration, as 

 also Milton's Mulberry at Christ College, Cambridge. 



Nitrification. — Reference was made by Dr. Gilbert to the presence 

 of an organism acting as a ferment in the process of nitrification, 

 and to the fact observed by Mr. Warrington in the Rothamsted 

 laboratory, that certain solutions were observed to contain nitric, 

 others nitrous acid. In some of the solutions vegetable organisms 

 were observed, and the curious point was, that in those solutions in 

 which the organisms were the nitrous acid had become further 

 oxidised into nitric, while in those solutions where there were no 

 organisms, the acid remained as nitrous acid. Dr. Masters stated 

 that he had examined three of the solutions containing organisms. 

 In the one case there were white flocculi, which on examination 

 proved to consist of crystals around which a profusion of micrococci 

 and a few hyphal threads were aggregated ; in a second case 

 mucilaginous films were seen floating in the liquid, and which when 

 examined proved to consist of micrococci and bacteria in the zooglsea 

 stage, together with numerous felted mycelial threads of extreme 

 tenuity. In the third case there were brownish specks, which under 

 the microscope were seen to consist of chains of ovoid cells, some- 

 what as in Spermosira. The specimens were referred to Dr. Cooke 

 for further examination and report. 



Simethis bicolor. — Dr. Masters exhibited a specimen of this plant 

 from Dorsetshire. It is considered a doubtful native, but is not 

 without geographical allies in the south-west corners of Ireland and 

 England. 



Sugar Cane Disease. — Mr. MacLachlan showed specimen of cane 

 from Queensland in which the tissue of the cane was eaten away 

 by the larva of a moth, which it was impossible to identify precisely 

 in the absence of the perfect insect, but it was probably one of the 

 Pieridae, like that which does so much damage in Mauritius. Two 

 remedies were suggested— one to pull up the canes and burn them, 

 the other to strip off the lower leaves, and to destroy the eggs of 

 the insect which are deposited in the axil of the leaf between it 

 and the stem. 



