278 Mr. C. II. Dolby-Tyler on the 



originally was a claret or light maroon, had changed to 

 a fulvous brown, and incipient development of the dorsal 

 tubercle was apparent in the more convexed and elevated 

 dorsum. 



The patches of dorsal secretion continued to grow, the 

 pro- and meso-thoracic ridges uniting in a well-defined 

 quadrangle, and several of the abdominal ridges becoming 

 confluent, until ten hours later they had attained a height 

 equal to that of the dorsum. During the ensuing fourteen 

 hours the quadrangular mass became cubical with a 

 concavity in its upper surface ; posterior to, and spring- 

 ing from the base of the cube, another ridge of secretion 

 had arisen and united accurately with the meta-thoracic 

 tuft ; and all the abdominal ridges were confluent and 

 serrated at their margin, showing on either side six 

 incisions corresponding to the tergal sutures. Though 

 distinct, the divisions between the regional masses of 

 secretion was inconsiderable. Six hours subsequently a 

 number of scattered nascent secretions appeared laterally 

 cephalad of the thoracic marginal tufts ; between the 

 thorax and abdomen a parallel and almost confluent ridge 

 of secretion appeared, inclined forward and united at its 

 apex with that of the meta-thorax ; while between the 

 pre-caudal lobes a short median film of secretion was 

 visible. Thirteen hours later several small patches had 

 appeared, marginally luterocaudad. At this stage in one 

 of the insects under observation I noticed a relatively 

 large drop of a transparent fluid ejected dorsally from 

 between the anal plates. 



Two days later (to be precise, 1J]0 hours after fixation) 

 the thoracic masses had united, becoming sub-conical 

 and inclined cephalad ; the lateral incisions of the 

 abdominal tuft had disappeared ; and the marginal tufts 

 could now be traced, although as yet the caudo-laterals 

 had not assumed definite form. The body of the insect, 

 now reverted to its original maroon colour, was visible 

 only as an ovoid fascia separating the dorsal and marginal 

 tufts, and united at its narrower diameter by the naked 

 thoraco-abdominal suture. 



The day following the marginal tufts, fifteen in all, 

 were quite distinct, there being six projecting laterally 

 from either side; one cephalad, below the cephalic tuft; 

 and one projecting posteriorly from beneath each pre- 

 caudal lobe. Meanwhile, the growth of the cephalic tuft 



