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Notes on Villi on the Scales of Butterflies and Mothb. 



By Dr. Royston-Pigott, M.A., F.R.S. 



(Bead January 27th, 1888.) 

 (Abstract.) 



The resolution of these difficult objects is a capital introduction 

 to the study of the minute structure of disease germs, and I can 

 strongly commend it to the attention of microscopists who have 

 neglected this department of natural history. Dr. Gabbett, of 

 Eastbourne, has made a large collection of germ slides, and has 

 succeeded in cultivating some very interesting micrococci closely 

 agglomerated in single layers. Each point appears perfectly 

 circular, and is finely edged with a minute jet black ring. The 

 thickness of this minute black test ring may be estimated at ■g-g-^ow 

 of an inch. But when the micrococci occur in several layers they 

 can scarcely be resolved, and no test rings are visible. This fact 

 demonstrates the extreme difficulty of resolving the minute bead- 

 ing existing in subjacent layers, as, for example, in the test 

 Poduras. 



Many of the villi in butterfly and moth scales are pawn-shaped, 

 possessing a base and a spherical summit. This form was the first 

 one discovered, with exceeding difficulty, on the scales of the Red 

 Admiral Butterfly. 



The scales of Amathusia Horsfeldii gave clearer indications, 

 but their extreme delicacy permits of no pressure being applied, as 

 it flattens and distorts them. After seven years' prosecution of the 

 research, I was rewarded with finding an entirely new vein, which 

 has proved very rich in material, in moths of the Zygcena tribe.* It 

 is rather difficult to arrange all their complicated forms methodi- 

 cally, and I shall therefore first sketch generally some of their re- 

 markable appearances. 



* There are about 100 species of this 'genus scattered over many 

 countries. Mr. Hinton, Vorley Koad, Holloway, has prepared a number 

 of slides, at my recommendation, showing many forms of beading, ribbing, 

 and villi. Mr Watkins, of Painswick, has also supplied me with 40 species 

 of Zygcena. 



