THE VICTORIAN NATURALIST. 9 



along until it reaches a straight portion, fixes a point on the edge 

 of its case to the branch, and also the diametrically opposite point 

 as far along the branch in the direction of the tree as convenient. 

 Without altering its position — that is, with its head towards the 

 stump, and its feet holding on to the part of the branch to be cut 

 off — the grub makes a V-shaped groove around the twig, taking off 

 first the bark, and then attacking the solid wood. The sides of 

 this groove have different slopes, as shown in diagram 3, that on 

 the side where the grub hangs being more nearly at right angles to 

 the length of the stick tlian the other, which is slightly concave. 

 Fig. 4 shows the stick cut through, the detached portion swinging 

 from the case, which hangs suspended from the branch. The 

 detached portion is now cut loose, and let fall as useless. Taking 

 hold of the branch, the grub trims up the end, detaches its case, 

 and walks back along the branch for a distance, generally returning 

 once or twice as if to check its length, and, proceeding exactly as 

 before, cuts off the piece required (figs. 6 and 7). Seizing it 

 firmly, it cuts the threads holding it to the case, trims up the end 

 and lifts it up, holding it slanting downwards towards itself, as in 

 fig. 8. With the second and third pairs of legs it passes the stick 

 downwards past its mouth, spinning a zigzag thread along it. 

 The first pair of legs are not much used to support the stick, but 

 follow the sideways motion of the head. When come to the end 

 (figs. 9 and 10) it turns itself around, without much altering the 

 position of the stick, lifts up the lower end, and proceeds, as 

 before, to spin another thread. After repeating this operation 

 some half-dozen times, it stops at the middle of the stick, drags 

 it down horizontally across the mouth of the case and lightly 

 fixes it there, as in fig. 11. 



Fig. 12 shows the next step in the process. The grub cuts a 

 longitudinal slit in the side of its case, through which it emerges 

 far enough to seize the stick and cut it free from the case. The 

 grub then withdraws into the case, and holding the end of the stick 

 close into the hole, sews both edges to it. The operation occupies 

 about one hour and a half, and is repeated until the sticks are placed 

 as close as can be around the upper end of the case, each one 

 fastened only at one end. By a similar process the sticks are one 

 by one fixed lightly along the whole length of the case, which, 

 when all are in place, is of its full size and shape, but very soft and 

 flimsy, requiring a liberal application of silk on the inside to make 

 it complete. The average dimensions of the case used by the male 

 larva are — -length, i'j4 inches ; diameter, ^-inch ; and that of the 

 female are — length, i^ inches; diameter, ^g-inch. 



The behaviour of this larva before pupation is similar to that of 

 M. elongata, the males attaching their cases firmly to the stems of 

 the. eucalypts, usually near the ground, during May, and the 

 females performing a similar operation higher up the trees. 



