( xlix ) 



the appearance at close quarters and determine 1 1 < > w far the 

 effecl was due to form and bow far to colouring. On return 

 ing from the visit of the British Association he wrote to his 

 friend Mr. R. I. Pocock, F.R.S., who had kindly observed the 

 Rheas in the Zoological Gardens and had seen the same effect 

 in some of them. It seemed likely, however, from .Mi'. Pocock's 

 account that the example at Perth was an exceptionally 

 favourable one : there was even suggested the appearance of 

 a dark iris on a paler eye-ball. It was quite probable that 

 the effect deteriorated under the conditions of captivity. 



[Shortly after the above paragraph was written, the follow- 

 ing observation was received from Mr. C. F. Swynnerton, 

 writing March 29, 1918, from Chirinda, S.E. Rhodesia. To 

 give an enemy the impression that its eye was upon him 

 would probably be advantageous to both Rhea and owl. — ■ 



" Talking of owls, I saw a very interesting thing once. I 

 had a live Glaucidium perlatum, an owl the size of a thrush. 

 One day, just after I got it, I offered it food in the forceps 

 through the wire of the cage. It did not take it, and looking 

 close, I found I was offering it to the back of the owl's head ! 

 The owl was asleep with its bill buried in its mantle-feathers, 

 but on the back of the head had appeared instead the 

 semblance of a bill and two great eyes, particularly the latter, 

 which were formed by two oval patches of black feathers on 

 the nape. I have little doubt that it is a case of mimicry, 

 though the resemblance is to such an owl as Syrnium wood- 

 fordi rather than to the Glaucidium itself. The latter is pale 

 round the eyes, the other dark. I sent an account of it 

 to the S.A. Biological Society's Journal a long time back, but 

 don't think thev have yet published. My idea is that, wdiile 

 it might make the Glaucidium more liable to be mobbed, it 

 will be useful in relation to birds of prey; for an owd that I 

 tested on my carnivorous mammals proved unpleasant to them 

 — not, of course, thai this is conclusive."] 



Many other observations on insects were contained in Dr. 

 Mortensen's paper. Thus it was extremely interesting to read 

 of the Membracid genus Sphongophorus : " I saw them often 

 alighting on leaves; they always fell on the side and then 

 looked in the most wonderful way like a small piece of rotten 



PROC. ENT. SOC. LOXD., Ill, IV. 1918. D 



