586 Mr Brindley, Further notes on the 



circulating mass beginning to burrow together occurred much more 

 frequently than the leader checking a procession by commencing 

 to burrow and its followers doing so after an interval. I may here 

 add to the descriptions already given of the action of a larva 

 burying itself that the chief movement of the body is dorso- 

 ventral bending as the sand is attacked with the mandibles, and 

 that the hind end of the body and the prolegs are the chief means 

 of brioging the excavated sand to the surface. The true legs seem 

 to shovel the loosened sand back to the prolegs. In one instance 

 in which the leader of a procession of seven commenced burrowing 

 its example was not followed. The second larva partially descended 

 the hole made by the leader but did not burrow. This continued 

 for 20 minutes, when the remaining six larvae marched away in 

 two processions of three each. The leader had quite buried itself 

 in 31 minutes. In two sets of observations on the same group of 

 larvae earlier in the day this particular larva had been remarked 

 as erratic and repeatedly straying from its fellows. 



I do not know any published statements on the time which 

 elapses between the beginning of burrowing and complete burial, 

 so I may mention that single larvae were seen to bury in 31 and 

 37 minutes, a group of 4 in 110 minutes, one of 7 in 120 minutes, 

 one of 12 in 85 minutes, and one of 21 in 110 minutes. Seven 

 larvae which had been buried for 48 hours were dug up ; one of 

 these completely reburied itself in 10 minutes and the other six 

 did so in 40 minutes. These larvae were from 3 to 4 inches deep 

 when first dug up and appeared to have added very little silk in 

 the two days. Fabre indicates that the cocoon is completed in 

 fifteen days. I brought a number of larvae, some of which had 

 buried themselves by April 2nd, in a biscuit box filled with sand 

 to Cambridge. The journey did not appear to interfere with 

 pupation, as by April 15th several had apparently completed their 

 cocoons. The imagos began to emerge from the sand on August 

 16th, and I placed them on a sapling of Pinus pinaster covered 

 with muslin in the hope that they would pair and lay their eggs 

 on the young leaves, but none of the moths lived long enough 

 to do so. 



While at Arcachon the larvae I kept in boxes refused to feed 

 on young pine leaves, but seemed quite as active after several days 

 starvation as when captured. Possibly feeding is given up as the 

 time for pupation approaches. 



As in 1906 and in agreement with Edwards' experience 

 I experienced no irritation from handling the larvae. No doubt 

 sensibility to the glandular hairs varies with the individual : 

 Fabre's own case, so vividly described iloc. cit. p. 378), is probably 

 exceptional. 



Very much conceraing the processional habit remains obscure. 



