5 o THE SCOTTISH NATURALIST 



to roam at will. During the ensuing spring they nested 

 and reared a cygnet, while the two following years they 

 reared three and four respectively. This year their breeding 

 was interfered with, owing to the drying up of the marsh 

 where they nested. People walked over the ground, and 

 the birds, being continually disturbed, did not attempt to 

 breed. Of the young birds born in the locality one 

 disappeared, another was pinioned and sent away, but the 

 remainder have settled down and so far have evinced no 

 desire to migrate, beyond trumpeting and becoming restless 

 as the time for wandering approaches. 



It has long been known that the Gold-tail Moth {Porthesia 

 shnilis) is liable to inflict upon a tender-skinned person 

 handling it an intense irritation and even inflammation 

 resembling nettle-rash. The caterpillar of this species is 

 also possessed of severe urticating properties to such an 

 extent that it is said to be risky to beat a hedge which has 

 harboured a colony, since the irritating particles cast by 

 the larva fly off, settle on the skin of hands and face, and 

 cause much suffering. In a paper recently published on 

 the subject by Dr Harry Eltringham, 1 much interesting 

 detail is brought forward as to the structure and origin of 

 the irritant particles both in the larva and the adult moth. 

 It appears that in the former each segment bears large 

 branched hairs, and at the bases of certain of these some 

 masses of peculiar barbed spicules which are very easily 

 detached, and appear to be then loosely retained by the 

 branched hairs. These spicules are the cause of the irrita- 

 tion, but whether this is due to chemical or purely mechanical 

 action (or both) appears to be yet uncertain. The most 

 remarkable part of the paper is that dealing with the adult 

 moth. The urticating properties (possessed by the female 

 alone) are due to the presence, in the anal tuft of hair, of 

 barbed spicules identical in structure with those found in 

 the caterpillar. From the observations of the author it 

 appears that the moth, by a remarkable instinct, actually 

 collects, while emerging, these spicules from the inside lining 



1 Trans. Ent. Soc, 1913, part 3, pp. 423-427, plate xxii. 



