Dec, igii.J Strickland: Development of Termes flavipes. 257 



see how they underwent their final ecdysis. Unfortunately the sudden 

 rise in temperature at this time had so accelerated the swarming 

 period that in every colony examined the nymphs had assumed the 

 adult form and many were already becoming pigmented. A few 

 nymphs and forms with outstanding wings were, however, found in 

 one or two colonies and these were taken to the laboratory. From 

 these it was seen that development proceeds as follows : 



The mature nymph becomes very sluggish and finally all move- 

 ment ceases; it then falls over on its side and the head is bent down 

 till it lies on the ventral side of the body, along which also the 

 antennae and legs are extended in a backward direction (Fig. i), while 

 the wing pads are bent downwards till they lie laterally along the 

 sides of the body (Fig. 2). It will be at once noticed that while in 

 this position the nymph is to all appearances a quiescent pupa libera. 

 There does not appear to be an ecdysis immediately prior to this qui- 

 escent period, however, so I would hesitate to describe it as a true 

 pupal state though it undoubtedly has the same physiological function. 



This quiescent stage lasted in the few specimens observed for 

 a period varying from four to about nine hours. The duration in 

 time seems to be controlled to a large extent by the amount of mois- 

 ture in the earth surrounding the pupa for when specimens were 

 placed in perfectly dry earth they were unable to pass beyond this 

 stage of development, while the greater the amount of moisture the 

 shorter the period. During this stage the last nymphal skin splits 

 across the head and along the dorsum, and is slowly worked down- 

 ward and backward till a large portion of it hangs freely from the 

 apex of the abdomen on the ventral side. The legs are the last part 

 of the body to be freed from this skin, which then becomes detached 

 as a much crumpled mass. As soon as the wings are liberated they 

 begin to move away from the body at their base. This is apparently 

 due to the tracheae in the basal portion of the wing becoming inflated. 

 The inflation, however, does not extend beyond the suture along 

 which the wing is subsequently broken off, and the distal portion re- 

 mains tightly folded as shown in Fig. 3. 



The ecdysis described above is the last in the development of the 

 imago for the insect now disclosed is the sexually complete adult; 

 it does not, however, become active as soon as it emerges but re- 

 mains for about a quarter of an hour in the same position as that 



