Iviii PROCEEDINGS OF THE 



bouring discoloration, first greenish, afterwards brown, spreading 

 to a distance from the line of perforation, and gradually becoming 

 fainter. The diseased part emits a peculiar odour, characteristic 

 of the taint and reminding him of that of sweet orris root, but is 

 hardly distinguishable by the taste from the sound portion, though 

 seeming to leave a just perceptible acrid after-taste. 



With regard to remedies for the disease. Dr. Davy found that 

 immersion of the larvae and beetles in lime water was fatal to both 

 in a few hours ; and hence he suggests immersing the potatoes 

 beginning to be diseased in this liquid for a sufficient time, and 

 then drying them by exposure to the sun and wind. He also 

 suggests as remedies immersing the diseased potatoes in very 

 dilute sulphuric acid and in a strong brine of salt, after being cut 

 in halves and quarters. The insect confines its attack to the 

 sweet potatoe, not being found either in the yam or eddoe ; and 

 the " vine" of the diseased potatoe remains strong and vigorous, 

 being unaffected by the state of the tuber, whose function is not 

 to aid in the growth of the parent plant, but to supply nourish- 

 ment to young ones growing from it. 



The President stated that the beetle sent by Dr. Davy to the 

 Society is a small species of the vast tribe of Ciirculionidce, not 

 exactly referable to any of the genera in the collection of the 

 British Museum, with which Mr. Waterhouse has compared it, 

 but were nearly allied to Ceutorhynchus than any other. As it is 

 most probably a new species, it is proposed to call it C. Batatce, 

 and its specific character will be given by Mr. Waterhouse. 



The President also exhibited specimens of a Calandra allied to 

 Cal. Oryzce, which destroys the grain of Sorghum vulgare. 



Mr. S. Stevens exhibited a box of insects collected at Para by 

 Messrs. Wallace and Bates, containing many rare and valuable 

 specimens. 



An extract of a letter from Brazil, addressed to Mr. W. F. Evans, 

 on the subject of the luminosity of Fulgora laternaria, was read. 

 The writer, though he had never seen the insect shine, yet be- 

 lieved in its luminosity. 



