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TUESDAY, August 6th, 2 p.m. 

 SECTION IL— MORPHOLOGY AND ANATOMY. 



President : P. P. Calvert. 

 Vice-President: J. C. H. de AIeijere. 

 Secretary : R. S. Bagxall. 



F. A. DixEY read a paper on : 



The Scent- PATCHES of the Pierix.e. 



The scent apparatus may be in the form of scattered " plume- 

 scales," or may occur as patches of specialised scales. Structure 

 and position of the patches in Dismorphia. Structure of the scales 

 in patches of Dismorphia {Acmcpteron) nemesis. The fact that 

 the patches are not visible when insect is at rest, and do not 

 contribute to the general pattern, is evidence that the pattern 

 has been evolved under natural selection. When the scales 

 have been removed, the wing still shows a pecuhar appearance, 

 due to the scale sockets, which differ from those on remainder 

 of wing. Structure of patches in Acmepteron virgo. In Dis- 

 morphia praxinoc. In D. fortunata. In D. pallidula. Tracheae 

 not evident in patches of Dismorphia, but present in several 

 other genera, e.g. Catopsilia, Colias, Teracolus, etc. Structure 

 of patch with tracheae in Teracolus fausta and Catopsilia flor ella. 

 Possible function of the air vessels. 



The paper was illustrated by lantern slides (cf. Vol. II., p. 336). 



Discussion. 



G. B. LoxGSTAFF said that he had observed scents in different 

 butterflies to differ not only in quality, but in quantity or volume, 

 and in duration. He thought it likely that the anatomical rela- 

 tions might prove to be chñerent in different species. 



J. C. H. DE Meijere remarked that he did not believe that 

 the air vessels had anything to do with the expulsion of the 

 odour, as the scent scales were connected with gland cells, and 

 in insects in general glandular regions were largely provided with 

 a quantity of tracheae. 

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