( iv ) 



Mr. Blandford discussed the various kinds of hairs on several 

 caterpillars, certain species having hairs of two kinds, one 

 kind being barbed, and thus having the power to work into 

 the skin. This was the case with Cnethocampa and Porthesia 

 similis; the urticating hairs in these species were from 

 •1 to '2 mm. in length, sharply pointed at the base and 

 finely barbed, the apex in the latter species being trifid. The 

 number of these hairs on a single larva of (7. processioned had 

 been estimated at 720,000. He said that the urticating 

 property of the hairs appeared to be mechanical : there was 

 no evidence of any poison glands. On this point the ex- 

 periments of Staff-Surgeon Liibbert (Judeich u. Nitsche, 

 Lehrb. der Mitteleur. Forstius., p. 907) appeared to him to 

 be conclusive. They showed that no reagent was capable of 

 extracting any irritating substance from the hairs, that they 

 retained their urticating properties without alteration and 

 indefinitely, and that these properties were unaffected by 

 treatment with acids, alkalies or other reagents, or heat, as 

 long as the structure of the hair remained unaltered. More- 

 over, hairs softened by prolonged maceration, e.cj., in alcohol, 

 lost their power of irritation, but regained it fully on being 

 dried. He had examined the two hairs extracted from the 

 eye of Mr. Lawford's patient, and found them to be identical 

 in all details with the shorter and stiffer hairs of the cater- 

 pillar of Lasiocampa ruhi. 



Mr. Lawford said he had had some difficulty in discovering 

 hairs in the lid, and he thought that the symptoms in the 

 case in question were not to be explained by mechanical 

 irritation alone due to the presence of hairs in the tissues. 

 The subject was a new one to him, and he had looked up all 

 the medical literature bearing on it. Lord Walsingham, 

 Mr. Tutt, Prof. Poulton, Canon Fowler, and Mr. Jacoby 

 made some remarks on the subject. 



Papers, etc., read. 



Dr. F. A. Dixey read a paper entitled " On the Relation of 



Mimetic Patterns to the Original Form," in which he 



dealt with (1) the Gradual Growth of a Mimetic Pattern ; 



(2) Sexual Dimorphism in Mimetic Forms ; (3) Reciprocal 



