NATURAL HISTORY OP LAKE ITEMI. 367 



surrounded by a circle of live coals and unable to escape, stung 

 itself in the head. Dr. Wills (' The Land of the Lion and the 

 Sun,' 1891, p. 249) even asserts that he has witnessed the suicide 

 of fire-girt scorpions on more than one occasion. Unfortunately 

 Dr. Wills does not designate the particular kind of scorpion with 

 which his experiments were performed. A solitary experiment 

 of my own, made with. JButhus caucasicus subsp. persicus at 

 Maragba, proved as unsuccessful as those whicb were under- 

 taken by Prof. E-ay Lank ester. 



The sting of scorpions is greatly feared, and peculiar pre- 

 cautions are taken against them in many places. Many stories 

 are told of deaths attributed to scorpions, but it is always difficult 

 to ascertain whether the venom was the sole cause or merely an 

 accompanying complication. However, it is certain that scorpion 

 stings are better avoided. In some parts dried thistles, spread 

 loosely under the beds, are employed in order to keep scorpions 

 away : indeed, many of the mountain folk of Kochanes bold that 

 a goat-hair blanket will suffice for this purpose ; since scorpions 

 have such a tender skin on their stomach that if they can be 

 made to walk over the hair of a goat, they will receive a " mortal 

 wound." 



Mimicry. — On August 19 I noticed some interesting cases 

 of what appeared to be protective coloration. Near tbe spot 

 where the Shaber Chai leaves the bills and enters upon its 

 course across tbe plain of Urmi, numerous poplar trees have been 

 planted. The bark of the Populiis alba is on the whole of a grey 

 colour, the ground being dark and sprinkled with light-tinted, 

 almost white stippling. Upon the bark of the trees were several 

 species of insects which so exactly mimicked the bark upon which 

 they were sitting that it was extremely difficult to distinguish 

 them from their background (PI. 27. fig. 1). The insects found 

 upon the poplar bark were Yponomeuta padellus, L., Pentatoma 

 iaccarum (?), and Batliyoscopus poceilus, H.-Sch. There were 

 also numerous spirally coiled shell-like larva-cases or cocoons of 

 Apterona crenulella. No other insects except ants were seen. 

 The Pentatoma, with its grey speckled thorax and wing, and 

 with its antennae barred alternately white and black, was more 

 invisible against the grey bark than its emerald-green relative 

 was upon the fresh green leaves of herbaceous plants near the 

 stream. 



