ANCESTR Y AND CLA SSI PICA TION. 249 



character of a single member of that family, the 

 group of swallow-tails. Nothing can exceed the 

 gorgeousness of the huge Ornithoptera of the 

 East Indies, and the most queenly of our own 

 New England forms are its nearest relatives. 

 They also show a unique development in the di- 

 minutive size of the palpi of the imago, in the pos- 

 session of four distinct branches to the median 

 nervure of the front wing [see Fig. 75], and in the 

 dorsal and extreme development of osmateria in 

 the caterpillar [see Fig. 32], to which we have 

 already alluded. But there is no reason whatever 

 for considering the brevity of the palpi or the 

 extra branch of the median nervure marks of high 

 organization, the one arising from deficiency, the 

 other from excess of development. On the con- 

 trary, in these very points they resemble the 

 skippers more closely than they do any other 

 butterflies, and these features are therefore traces 

 of their low organization. The possession of the 

 peculiar scent-organ, however, is unquestionably 

 a mark of high development. Wallace writes : 

 " When we consider this singular apparatus, 

 which in some species is nearly half an inch long, 

 the arrangement of muscles for its protrusion and 

 retraction, its perfect concealment during repose, 

 its blood-red color, and the suddenness with 

 which it can be thrown out, we must, I think, be 

 led to the conclusion that it serves as a protection 



