( clxxiv ) 



that 1 was aide to approach my nose to within two or three 

 inches of a third with tufts extruded. I experienced a sensa- 

 tion as if an aromatic snuff had impinged on the mucous 

 membrane of my nostrils. Subsequently 1 seized by one wing 

 a fourth butterfly with tufts extruded. They remained ex- 

 truded in spite of its struggles, and on smelling them I 

 experienced the same sensation."' 



The movements described in this valuable record strongly 

 supported Dr. H. Eltringham's interpretation, in Trans. Ent. 

 Soc. Lond., 1913, p. 404, based on an examination of the 

 structures in the laboratory : — 



" We may suppose that the insect brushes out the secretion, 

 the stiffer [darker] hairs probably assisting in lifting the 

 covering scales. ... It should be noted that these hairs are 

 on the outer side of the brush, and would thus naturally 

 come first into contact with the scent-patch." 



Dr. Eltringham's researches showed that there was no 

 special muscle directly concerned with the protrusion of the 

 brushes. This was effected, as in many similarly eversible 

 glandular and odoriferous structures, by the pressure of the 

 fluids of the body. The constricted 11th and 12th segments 

 and the peristaltic waves of contraction described by Mr. 

 Lamborn were doubtless instrumental in producing this 

 pressure. 



A SUGGESTED INTERPRETATION OF THE SPECIAL ATTACKS 

 MADE BY BLOOD-SUCKING DlPTEKA OX NEW-COMERS INTO THE 

 TROPICS AND OF THEIR CRADUAL DIMINUTION.- -Prof. POULTON 



said that he had received the following suggestive notes from 

 Mr. C. B. Williams, who had written from the Department 

 of Agriculture, Trinidad, B.W.I, on Oct. 12, 1918: 



" 1 got last mail Parts II, III and IV of the Trans. Ent. 

 Soc. for L917 (somewhat delayed!), and was particularly 

 interested in a discussion (pp. lxxvii et seq.) on the attraction 

 of insects to salts, perspiration, urine, etc., because it largely 

 fits in with some of my own ideas and observations on the 

 subject. 1 have ventured a little further, and have developed 

 a theory which appeal's to me to be sound. It is that relative 

 resistance to mosquito bites is due to differences in the com- 

 position, and hence the scent, of the perspiration, and further 



