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left the slit ! Either, therefore, the exhibitor had been mis- 

 taken in his former observations (though they were made so 

 carefully and repeated so often that he hesitated to believe 

 this), or possibly the phenomena may really be different in 

 different cases, as for instance when the stems operated upon 

 differ in thickness, and therefore in the curvature of that part 

 of their surfaces which is affected. 



It has sometimes been stated that the attachments of the 

 two so-called " saws " are such that when one of them ad- 

 vances the other must necessarily retreat. Frequent dis- 

 sections of these organs had long made him feel sure that this 

 was a mistake, and he could now say quite positively that it 

 is so. On more than one occasion he distinctly saw one of 

 the two blades advance and retire and again advance, while 

 the other blade remained absolutely at rest with its apex 

 touching the apex of the (motionless) supports. 



He noticed also, on one occasion, that the cuticle became 

 separated from the underlying substance of the stem along 

 a line which the advancing edge of the saw had not yet reached ! 

 This had confirmed him in the belief he had always held, 

 that the action of the " terebra " is not simply cutting, but 

 includes a sort of splitting — in short, that it acts as a " wedge," 

 and that in this part of its work the stout thick " supports " 

 take at least as much share as the delicate and slender " saws." 



Dr. Chapman and Messrs. E. E. Green and Bethune- 

 Baker commented. The President and Mr. C. J. F. Fryer 

 both observed that they had received larvae of Sirices from 

 growing trees in England. 



Further Note on the "Death-watch" Beetle. — The 

 President remarked that the Xestobium which he had 

 exhibited at the previous meeting was still living, and that 

 he had discovered that it was a $. It had tapped when 

 touched on the head with a bit of paper, and when this was 

 continued had extruded its ovipositor. 



Many different statements had been made by different 

 observers as to the part of the head used in tapping; these 

 were probably all correct, as the part of the head employed 

 depends on the form of the surface tapped. 



Mr. Donisthorpe commented on these observations. 



