108 ■ GEO. D. HULST. 



steninied or separate. In the individual species considerable varia- 

 tion exists, so that in the same species in the fore wings 4 and 5 may 

 he joined or separate, and in the hind wings 7 and 8, and 8, 4 and 

 5 are subject to the same uncertainty of position. 



So far as my knowledge goes after the comparative examination 

 of very many individuals of the same species, I regard the venation 

 pretty constant in the most of the s[)ecies. I have seen scarcely any 

 exception among those having 10 and 9 veins in the fore wings. 

 The variation in fact is not very great any where. It is merely a 

 I'eaching out in each direction from the average position. I know 

 of no case where veins are in the same species long stemmed and 

 separate ; or well separated, and at all stemmed ; but in many cases 

 where the veins of the species are ordinarily short stemmed, speci- 

 mens may be found where the veins are from a point, or really sepa- 

 rate though close ; and again, where the veins are ordinarily close, 

 but separate, specimens may be found where they are short stemmed. 

 The most variability is in 10 with 8 and 9 in the fore wings, and 3 

 with 4 and 5, and 7 with 8 in the hind wings ; but 4 and 5 of both 

 wings are not to be too nuich relied upon as being constant in posi- 

 titm. 



There seems to be more than usual a tendency to wide aberrations 

 in venation. I have found two specimens where there were 12 veins 

 in tlie fore wings, and one or two abnormal cases of sten)ming. 



There is a very decided diftei'ence of opinion as to what vein is 

 lost in the case of the obsolescence of one of the lower median series. 

 Up to the time of Mr. Ragonot, the usual statement was that vein 5 

 was the one lost. This was the case in the Geometridse, and the 

 older s^'stematists probably thought this as well true in the Phyci- 

 tidse. Mr. Ragonot, however, in his paper CDiag. N. A. Phyct. p. 

 2, 1887) says, speaking of the hind wings, " Vein 5 exists always, as 

 the space between 5 and 6 is ever of the same breadth whether the 

 median vein be trifid or quadrifid." 



In this matter I agree entirely with Mr. IVleyrick, who says the 

 two veins become "coincident." The obsolescence of the vein, 

 which ever it be, is not because it is droi)])ed out, but because it is 

 stemmed with its neighbor, and the stem is so long that the ])()int of 

 separation is carried beyond the edge of the wing; and while it is nearly 

 true, as Mr. Ragonot says, that "the space between 5 and (5 is ever 

 of the same breadth," it is entirely true that the union has carried the 

 resultant through all its course further from 0. This is shown also 



