1899] ENTOMOLOGICAL SOCIETY. 81 



ing together on the inner side ; but their true structure can be clearly demonstrated in 

 an unexpanded wing. And here I will express the opinion that the term " veins " is 

 inappropriate and quite misleading as to their purpose and use. 



The most recent statement upon this subject that has come under my notice is in an 

 article by Henry Charles Lang, M.D., M.R.C.S., L.R.C.P., London, England, in the 

 August number of Science Gossip, 1899, page 71, from which I will copy the paragraph 

 headed, " The Vascular System : " 



" This in butterflies is of a very simple character. The centre of the circulation is a 

 rudimentary heart called the ' dorsal vessel,' situated on the dorsal surface of the abdo- 

 men and divided into several chambers, It is controlled by muscles attached to the abdo- 

 minal walls, and by their action the blood is propelled into the aorta, which is a prolonga^ 

 tion of the dorsal vessel, having the form of a tube passing through the thorax to the 

 head. The blood then returns through the lacunae or interspaces of the various organs 

 to the abdominal sinus which surrounds the dorsal vessel and thence into the vessel itself 

 through special valvular openings. There are, in insects, neither arteries, capillaries, nor 

 veins in the true sense of the word, and the blood is cold, colorless and not corpusculated. 

 As above stated, it is usually held that in butterflies the nervures of the wings convey the 

 blood to these appendages, until they are fully unfolded after the emergence of the insect 

 from the pupa. Circulation through these then ceases, the texture of the wings becoming 

 dry and nonvascular. The nervures then perform the functions of air tubes." The italics 

 are mine, and what I desire to call attention to is, that it is now time to cease disseminat- 

 ing that bit of misinformation. "We have now attained to a fairly clear conception of the 

 wing structure of this particular butterfly, and the question now to be settled is, are 

 all butterflies' wings constructed on the same principle ? It seems highly probable that 

 they are, but positive proof is wanted; and I now consider it an easy matter to get it by 

 anyone who can obtain a specimen in the proper condition. And as an inducement for 

 anyone inclined to follow up the subject, I would recommend it to them as a most fascin- 

 ating field of observation, and one well calculated to yield profitable results. 



The photograph for the plate prefixed to this volume, was taken by Mr. R. W. 

 Rennie, London, Ont., who, amongst his other accomplishments, is an expert amateur 

 photographer. 



Description of the Plate. 



Fig. 1. Presents the inner sides of upper and lower membranes of a front and hind 

 wing. These were separated under water and the gummy fluid washed off so the color of 

 the outer surface shines through. 



Fig. 2. The inner side of the lower membrane of a front wing. 



Fig. 3. The hind wing of a male, disclosing the inside of the sexual spot. 



Fig. 4. The inner side of an upper membrane of a front wing. 



Fig. 5. The inner side of the lower membrane of a female's wing. These four 

 membranes were separated as best I could before I tried it in water, the gummy fluid 

 over the whole inner face of the membrane giving them a whitish appearance, as if they 

 had got a thin coat of varnish. 



Fig. 6. Shows the inner sides of the two membranes of an unexpanded front wing, 

 with the basal portion of the costal membrane not separated. Its exact length is five- 

 eighths of an itch. 



Fig. 7. Gives a view of the natural size of a perfect front winglet. The opposite one 

 is incomplete. 



Fig. 8. The underside of a hind winglet. The opposite one is the upper side of 

 another ; both imperfect. 



Fig. 9-10. Are the wings of one butterfly. The length of front wings from base to 

 apex is two inches, by one and a quarter wide at the outer angle. 



Upon one occasion, when engaged in separating some of the membranes, the inner 



sides of which, upon being exposed to view, had a reddish, raw appearance, a friend 



who had been intently watching the operation for a time, turned away with the remark, 



" Well, it's got down to a pretty fine thing now, when you've taken to skinning them !'» 



6 EN. 



