194 PLUM. 



outer wood, this clianiljci- l)eing about tliree-quarters of an 

 inch l)y onc-quavtor in dimensions of widtli, and in thickness 

 only about sullicient to accommodate the full-grown larvae or 

 beetles ; and patched over the surface with the white fungoid 

 formation known by writers as "Ambrosia," this being 

 sprinkled with workings of wood-dust, or " frass " of wood. 



The smallest size of larva that I measured in the numerous 

 collection was just over the thirty-second of an inch in length; 

 and 1 found upwards of fourteen larva; packed together in the 

 inner part of the slit-like cavity, and perhaps a dozen or 

 more besides. From the extreme narrowness of the chamber 

 it was difficult to dissect out the specimens so as to be sure 

 of amount of contents. 



I found amongst the above larvfe three pupte ; these were 

 readily observable, even with moderately magnifying glasses, 

 by their l)right shiny whiteness ; the hinder edge of the 

 thorax was well defined, and so was the longitudinal striation 

 of the wing-cases. The shape is that of the future beetle, only 

 still lying at rest with the developing limbs folded beneath it. 



The flat and narrow form of the brood chambers, as figured 

 at 8 and 4, p. 102, is characterisiic. 



In another piece of Plum stem, of two and three-(juarter 

 inches in diameter, which I examined about the same date, I 

 found a horizontal tunnel running from the outside, of about 

 a quarter of an inch in length, on each side of which, 

 beginning at the above distance (one-quarter inch) from the 

 outside of the tree, a flat vertical cell was hollowed out. 

 three-quarters of an inch long at the greatest height, and 

 five-eighths in width. The shape of this flat chaml)cr was 

 somewluit squarish (see figure JJ, p. 192), about two-thirds of 

 it being above, and one-third below the mother gallery, of 

 which some traces still remained, and which crossed the flat 

 cell, and then was continued merely as a tunnel (a distinct 

 gallery) for about three-eighths of an inch further, where it 

 stopped, the extremity being filled witli about half-a-dozen 

 very young larvjc and a few eggs. 



The surface of the Hat chamber (as seen in the side re- 

 maining after the other side had been cut away in the course 

 of examination) was covered for the most part with a very 

 thin coating of wax-like material, greyish in colour, and with 

 a somewhat sweet scent, and the surface of the wood of the 

 clianil)cr, wherever it was visible, was certainly not of the 

 bla(;k colour so noticeable in connection with the workings of 

 X/jlehoriis dispar. It was rather of a brown colour, and 

 moist-looking appearance. This flat cell, or gnawed-out 

 chandler, had only space enough between its two upright 

 sides (see figure 4, p. 192) to accommodate the larva), which 



