730 Michael F. Guyer 
distinct and broader V-shaped white barring is well developed near 
the baseof the feather (Fig. 25, Plate IV) as in certain feathers of 
the normal domestic guinea already described. 
Indications of the finer Agelastes-like barring are to be found on 
many feathers of the neck in other species of Numida and, what ts 
of further significance, they are well developed on certain feathers 
of the upper back and lower neck of a species belonging to a still 
different genus, namely Acryllium vulturina. ‘This species is pro- 
fusely decorated with white dots of somewhat smaller size than 
those of Numida. However, on some feathers of Acryllium, certain 
feathers of the wings, for example, there are pronounced longitud- 
inal stripes. ‘This is evidently a progression beyond the condition 
of spotting because, as is evidenced in the series of young in the 
Muséum d’histoire naturelle, the striping appears later instead 
of earlier in the development of the color pattern of the adult 
plumage. In the half-grown young, for example, the feathers dis- 
play a wholly barred pattern except for a few dots on tail and 
wing which have evidently been derived from earlier bars. The 
white bar in Acryllium vulturina of which the dots are a product 
is intermediate in breadth between the slight marking of Agelastes 
meleagrides and the heavier bar of Numida meleagris. 
An examination of such a feather as that of Numida meleagris 
pictured in Fig. 28, Plate IV, shows how the dotting derived from 
ihese bars passes readily over into a pattern of longitudinally 
arranged dots which in later evolution might become stripes, a 
progression which has already become an accomplished fact in such 
feathers of Acryllium as are striped. 
Ai aking this evidence all together one seems justified in soncleee 
ing that in certain of the guineas (Agelastes, Numida, Acryllium) 
_there is or has been a primitive white barring of the feathers and 
that in the three peculiar individuals recently under discussion, 
more or less of a reversion to this pattern has taken place, or in 
other words, the color pattern has for some reason stopped short 
of its fullest development. It seems likely, furthermore, that in 
these regressive individuals, we find traces of two types of barring, 
namely the finer barring (Figs. 22, 25, 26, Plate IV) similar in 
appearance to that of Agelastes meleagrides, and a heavier barring, 
