NINTH ANNUAL REPORT. 219 
against the sides of the body. When this area is truncal in ex- 
tension, or when small apteria are present in adjacent parts of 
the body, the condition is either wholly vestigial, or dependent 
on the action of the legs. This remarkable obliteration of apteria 
(which is paralleled only by the Penguins, and the horned 
screamer among the Carinatae) is, without doubt, only a sec- 
ondary primitive character, although there is not that difference 
in the pterylosis of the embryo and the adult, which we might 
expect. The ventral apterium is fairly well developed in the adult 
Apteryx, which does not rest on its sternum and thus has no 
sternal callosity. 
As special adaptations of degenerate feathers, are to be noted 
the well-developed eye-lashes of Ratite birds, especially in the 
case of the Ostrich. They may perhaps be necessary, even in 
addition to the nictitating membrane, in keeping the eves clear of 
dust, which would be abundant in the deserts and plains of Africa. 
The elongate, hair-like, facial feelers and rictal bristles of the 
Apteryx are, of course, metamorphosed feathers, and subserve 
the function of touch—most important in this nocturnal, vermiv- 
orous bird. 
B. Remiges—The remiges, as we might expect in structures 
whose sole original function has disappeared, have either dimin- 
ished in number or run rampant. In one case only (the Casso- 
wary) is there a suggestion of change of function, or adaptation 
to new conditions, although there is just a suspicion that the 
increase in number of the remiges of Struthio and Rhea may have 
some such significance. 
It is evident that the ancestors of the Ostrich and the Rhea 
used their wings to a much later time than did the forebears of 
the Emeu, Cassowary and Apteryx. The only data for com- 
parison which we have at present is the number of remiges in 
the Archaeopteryx, and the extreme variations which exist among 
the Carinatae. The following table will present the matter 
clearly : 
y PRIMARIES. SECONDARIES. REMIGES. 
@ stihl waa esse 16 20 207 
RinGaeut eis Sou oe 12 16 28 
Ea GKE Ua aa ee eee i 10 ity 
ENPCEEYS (asic een aie - 4 G 17 
@assowary «Aes. : 3 ai 6 
J MECHAcOpleny qos. 5 0 OL-7 IO 16 
Humming-bird .... 10 6 16 
PNUD ATT OSS erases oes: (50 10 30-40 40-50 
* In one male bird which I examined there were no less than forty-one. 
