26 MR. R. J. TILLYARD : LIFE-HISTORIES AND 



Steady myself to strike. At the most it could only have been two or three 

 seconds, which gives these insects the almost incredible speed o£ about 

 sixtv miles an hour. Owino- to the excitement of watching; their on-comino- 

 and the impossibility o£ calmly counting off accurate seconds in one's mind, 

 I cannot give an exact time, but I do not think that I have erred far in 

 stating their speed. 



As regards the manner of flighty the males keep very close to the water — 

 not more than a foot above it. Coming straioht towards the observer, the 

 body, as w^ell as the wings of the insect, is almost invisible, being dark brown 

 against a very similar background. The insect approaches as a rapidly 

 pulsating shadow, each pulsation being a very small vertical rise and fall, 

 occupying pei'haps a fifth of a second, and representing one dart or jerk 

 forward of the wings. Standing away from the creek and observing the 

 insect sideways, the body is slightly more visible, and the jerks can be 

 plainly seen, each bearing the insect forward for a considerable distance. 

 These jerks are only made when the insect is being impelled forward straight. 

 In rounding the edge of a pool, the wings are held in a plane slightly inclined 

 from the horizontal towards the momentary centre of curvature of the path, 

 and the jerks recommence, often with a sharp crack, as soon as the horizontal 

 position is again assumed. No effort at all was apparent in passing over 

 vertical obstructions, such as low rocks in the bed of the creek. Poising or 

 hovering, however, is not so easy to these insects as to some of the smaller 

 udEschnince. I seldom saw a male stationary ; but when they do poise, there 

 is a distinct effort both to stop and to start, not infrequently accompanied by 

 a sharp crack or a whirring noise from the rapidity of wing-movement. 



The earliest time of day at which I saw this insect in flight (apart from 

 occasionally disturbing resting females in the morning) was about 1 o'clock 

 on a dull stormy day. They seldom fly at all until 4 P.M., but from that hour 

 to sunset they are particularly active. At all times they avoid the open or 

 sunny parts of the creeks, and keep to the deeply shadowed portions, along 

 which their remarkable colour-scheme serves to render them so little visible. 



I had several opportunities of observing the efficiency of this coloui'- 

 scheme when the insect is at rest. The favourite resting-place of the species, 

 and especially of the females, is the underside of a large tree-fern frond. 

 The colour of the midrib is exactly that of the Dragonfly's body, and the 

 four brown bands along the extended wings give them just exactly the 

 appearance of four brown twigs. Once I disturbed a female which flew up 

 on to the underside of a tree-fern frond only a few feet from me ; but I was 

 quite unable, in the poor light, to make out the exact spot ; though as soon 

 as I touched the frond the insect darted out quite close to me. Other 

 favourite resting-places of the females are on the underside of large fallen 

 logs spanning the creeks, and also fairly high up on the smaller branches of 

 trees, where they are almost invisible. 



