. The butterfly book; a popular guide to a knowledge of the butterflies of North America. Butterflies -- North America. The Life-History and Anatomy of Butterflies costal, known as the subcostal, and the other preceding the sub- median, known as the median vein. The branches of these com- pound veins are known as nervules. The median vein always has three nervules. The nervules of the subcostal veins branch upwardly and outwardly toward the costal margin and the apex of the fore wing. There are always from four to five subcostal nervules. In the hind wing the subcostal is simple. The median ve
. The butterfly book; a popular guide to a knowledge of the butterflies of North America. Butterflies -- North America. The Life-History and Anatomy of Butterflies costal, known as the subcostal, and the other preceding the sub- median, known as the median vein. The branches of these com- pound veins are known as nervules. The median vein always has three nervules. The nervules of the subcostal veins branch upwardly and outwardly toward the costal margin and the apex of the fore wing. There are always from four to five subcostal nervules. In the hind wing the subcostal is simple. The median vein in the hind wing has three nervules as in the fore wing. Be- tween the subcostal and the median veins, toward the base in both wings, is inclosed the cell, which may be wholly or partially open at its outer extremity, or closed. The veinlets which close the cell at its outward extremity are known as the discocellular veins, of which there are normally three. From the point of union of these discocellular veins go forth the radial veins known respectively as the upper and lower radials, though the upper radial in many genera is emitted from the lower margin of the subcostal. An understanding of these terms is, however, more readily derived from a study of the figure in which the names of these parts are indi- cated (Fig. 40). Butterflies generally hold their wings erect when they are at rest, F>G. 4°-—Wing of with their two upper surfaces in $S*5"M c™C, "co'.d proximity, the under surfaces alone veins ;SC, subcostal vein ;SCi, etc., displaying their colors to the eye. ffi?3£S£^fiJJK£ Only in a few genera of the larger veins; MI, M2, M3, median ner- butterflies, and these tropical species, ^ ^"^Sd '£ with which this book does not deal, vule; UDC, MDC, LDC, upper, is there an exception to this rule, lle' and save in the case of the Hesperiidcv, or "skippers," in which very frequently, while the anterior wings are folded together, the posteri
Size: 1304px × 1917px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorhollandwjwilliamjacob, bookcentury1800, bookdecade1890
