Auk 
36 CHADBOURNE oz Individual Dichromatism. ae 
and ¢, fig. 5, and cut in text). In the white parts of the vane, the 
only color was a pale straw-yellow almost entirely limited to the 
outer (peripheral) cellular tissue, and probably caused by the 
Two Barbs from near A., pl. I, fig. 1. Groups of dark colored cells are seen 
in some parts of the barbs. (Zeiss 16mm. apochromat. and No. 6 comp. oc.) 
WE homogeneous stain (Plate I, fig. 1). The downy parts of the con- 
tour feathers had nodular enlargements at regular intervals, in 
which the coloring matter was usually collected (Plate I, fig. 4, 2); 
in other specimens the nodes were almost colorless, and the inter- 
nodes pigmented (Plate I, fig. 4,@). There seems to have been an 
absolute loss of black, as well as of the darkest brown granules 
