. Carnegie Institution of Washington publication. . Fig. 22.—Relation between melanism of second abdominal segment and clypeus of female. Cold Spring Harbor collection. FtG- 23.—Relation between melanism of second abdominal segment and clypeus of female. Willow Grove collection. These three species stand in the relation of albinic extremes to the three groups—rubigi?iosiis, aurifer, and canadensis—and appear to have been produced by similar conditions in these three different groups of the genus. Finally, I have been impressed with the mixed condition of the species for the upper half of the M

- Image ID: RFRWJ5
. Carnegie Institution of Washington publication. . Fig. 22.—Relation between melanism of second abdominal segment and clypeus of female. Cold Spring Harbor collection. FtG- 23.—Relation between melanism of second abdominal segment and clypeus of female. Willow Grove collection. These three species stand in the relation of albinic extremes to the three groups—rubigi?iosiis, aurifer, and canadensis—and appear to have been produced by similar conditions in these three different groups of the genus. Finally, I have been impressed with the mixed condition of the species for the upper half of the M Stock Photo
Enlarge
https://www.alamy.com/licenses-and-pricing/?v=1 https://www.alamy.com/carnegie-institution-of-washington-publication-fig-22relation-between-melanism-of-second-abdominal-segment-and-clypeus-of-female-cold-spring-harbor-collection-ftg-23relation-between-melanism-of-second-abdominal-segment-and-clypeus-of-female-willow-grove-collection-these-three-species-stand-in-the-relation-of-albinic-extremes-to-the-three-groupsrubigiiosiis-aurifer-and-canadensisand-appear-to-have-been-produced-by-similar-conditions-in-these-three-different-groups-of-the-genus-finally-i-have-been-impressed-with-the-mixed-condition-of-the-species-for-the-upper-half-of-the-m-image233479629.html
. Carnegie Institution of Washington publication. . Fig. 22.—Relation between melanism of second abdominal segment and clypeus of female. Cold Spring Harbor collection. FtG- 23.—Relation between melanism of second abdominal segment and clypeus of female. Willow Grove collection. These three species stand in the relation of albinic extremes to the three groups—rubigi?iosiis, aurifer, and canadensis—and appear to have been produced by similar conditions in these three different groups of the genus. Finally, I have been impressed with the mixed condition of the species for the upper half of the M
Book Worm / Alamy Stock Photo
Image ID: RFRWJ5
This image is a public domain image, which means either that copyright has expired in the image or the copyright holder has waived their copyright. Alamy charges you a fee for access to the high resolution copy of the image.
. Carnegie Institution of Washington publication. . Fig. 22.—Relation between melanism of second abdominal segment and clypeus of female. Cold Spring Harbor collection. FtG- 23.—Relation between melanism of second abdominal segment and clypeus of female. Willow Grove collection. These three species stand in the relation of albinic extremes to the three groups—rubigi?iosiis, aurifer, and canadensis—and appear to have been produced by similar conditions in these three different groups of the genus. Finally, I have been impressed with the mixed condition of the species for the upper half of the Mississippi Valley. The Missis- sippi Valley is emphatically a transition zone between the aurifer type of the West and the pallipes type of the East. Specimens gathered in this valley fall into the species aurifer and variahis or pallipes and metrica, according as they incline to the western or the eastern type of coloring; but, as I have shown (pp. 12-33), representatives of both types are repeatedly obtained from the same nest; also in different parts of this area the species vary in a fashion parallel to their vari- ation in other parts of the country. Thus the divergence in southern Illinois is, on the one hand, toward the aurifer type with a large. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Carnegie Institution of Washington. Washington, Carnegie Institution of Washington