1916] Chandler: Structure of Feathers 351 
tiation between base and pennulum, no ventral barbicels whatever, 
and a series of very highly developed flexules and dorsal cilia, in 
a continuous series after the hooklets are lost. Plate 26, figures 
52e and f shows the tardiness of the hooklet cells to develop any 
dorsal cilia. Plate 26, figures 52g and h show the method of trans- 
formation of the proximal barbules, the distals and proximals being 
exactly the same on the distal half of the barbs. 
In the Aramidae, as typified by Aramus giganteus, the barbules 
of the back feathers closely resemble those of the back feathers of 
the Coraciidae and Megapodidae in that in the distal barbules of 
the undisturbed vanules the bases are twisted in such a way that 
although at the junction with the ramus they stand in a vertical 
plane, they he in a horizontal plane for most of their length. The 
distals also resemble somewhat the ‘‘peristeropode’’ Galli in the 
curved form of the ventral cilia (compare plate 26, figure 51a, with 
plate 24, figures 45a and 46a). The proximals (pl. 26, fig. 51b) 
also approach the condition in these birds in their elongate taper- 
ing bases, and very short pennula. The breast feathers have bar- 
bules which resemble those of rails in the great development of the 
dorsal series of barbicels, consisting of both flexules and dorsal 
cilia, but are a little closer to those of the cranes in that they are 
elongate, and possess a highly developed series of ventral as well 
as dorsal cilia (pl. 26, fig. 51e). Plate 26, figures 51¢ and d show 
the distal and proximal barbules respectively at the base of a barb 
of a breast feather, showing the method of development of the 
peculiar type shown in figure 5le of the same plate. 
In Otis tarda, representing the Otididae, the remiges are char- 
acterized by the remarkable width of the pithy part of the ramus. 
On the inner vane, on barbs not over about 6 em. long, the ramus, 
near its base, is about 1.5 mm. wide, of which the ventral ridge 
forms a very narrow edge, being less than 0.05 mm. wide. The 
distal barbules of the remiges are peculiar in their being relatively 
short, with stout bases and very large, lobate ventral teeth, and 
exceedingly long hooklets, usually seven in number. They are 
devoid of conspicuous basal dorsal cilia even on the inner vane. 
The proximal barbules (pl. 27, fig. 53b) have a relatively large 
base, with a rather stout, moderately long pennulum. The back 
feathers are distinctly like those of galline birds in the structure 
of their barbules, the distals having both base and pennulum shaped 
as in the back feathers of Gallus, and the nuclei distinct in the 
