THE CANADIAN ENTOMOLOGIST. 45 



and at 5.31 settled on another leaf nearer the end of the twig. Here the 

 setae were inserted and secretion was renewed. At 5.45 it moved again 

 and crawled back nearer the end of the old wood and took up its tinal 

 position lengthwise between the bases of two leaves. At 7.30 it had 

 shifted its position to the other side, and there was no noticeable secretion. 

 At 5.45 the next morning (May 14th) it was still in the same place and 

 entirely covered with its secretion. 



During the process of secretion the fluid flows slowly along the 

 venter from a point near the anal opening, and gathers between the legs. 

 where, by their alternate agitation, it becomes mechanically mixed with 

 air and forms the cushion of air-bubbles. 



Another nymph was taken at 3 p.m. on the i4lh from its position 

 beneath the protective mass and placed at an inch from the end of a 

 limb ; it crawled about two inches further down and settled with its head 

 close to the base of a leaf, where it immediately inserted its setse ; 

 secretion began at once, but was hardly perceptible until about 3.15, 

 when a cushion of air-bubbles was noticed under the thorax and abdomen, 

 especially surrounding the lower half of the latter. The insect then 

 lowered the tip of the abdomen until the anal opening was under the fluid, 

 when it began to generate bubbles of air, each bubble being followed by a 

 dip in and out of the tip. This dipping in and out of the fluid was 

 followed at short intervals by extensions of the abdomen, apparently to take 

 in air, and then was renewed. The following count was made : 77 

 continuous dips producing 77 bubbles, then an extension, followed by 60 

 continuous dips. 



By thus blowing out the fluid, it gradually submerged the abdomen 

 and the rest of the body (3.37 p.m.). After the nymph was covered, the 

 secretion of fluid and exudation 'of air continued until the body was 

 completely hidden ; the secretion was afterwards steadily maintained, for 

 if it were not it would soon dry up. It is evident that the air is taken in 

 at each upward and outward dij) of the abdomen, and let out in the form 

 of a single bubble at each inward and downward dip into the fluid. 

 During this dipping process the ventral anal plates are in transverse 

 motion like jaws, and it is probable that the secretory glands are between 

 them. 



The nymphs have the habit of extending the abdomen at regular 

 intervals beyond the frothy mass ; this is also done when ihey are walking. 

 Their locomotion is slow, tedious and deliberate, but they can move quite 

 fast, in a rambling fashion, when they are disturbed. Their position in 



