10 ALP—ALTRICES 
allantois shrivels up, and is cast off with the shell; its stalk or 
urachus, from the cloaca to the navel, is gradually absorbed, there 
being no urinary bladder in Birds (see EMBRYOLOGY). 
ALP, otherwise ALPH, AWBE, or OLPH, a word of unknown 
origin, but of long standing (see Chaucer, Romaunt of the Rose, circa 
1400), and still locally used in one or other of its forms, e.g. “ Blood- 
Olph” and “Green-Olph” for the BULLFINCH and GREENFINCH 
respectively. 
ALTRICES, the name given by Sundevall (K. Vet. Acad. Hand. 
' 1836, p. 64) to his first section of the Class Aves, comprehend- 
ing those which “alunt pullulos” (feed their young), founded on 
the scheme of Oken (Lehrb. d. Zoologie, p. 371), in opposition 
to PRA&COCES, the birds which at birth are more or less able to feed 
themselves, but subsequently abandoned by its inventor (Tentamen, 
p. xx., Nicholson’s transl. p 26). 
The division of the Class thus indicated has under various 
names been advocated by several authorities, and at first sight has 
a plausible appearance; but investigation shews that it cannot be 
adopted. Doubtless the original Birds, like Reptiles, were Precoces, 
and the Alirices are of later date. The existence of the numerous 
intermediate forms may thus be explained; but it follows that we 
cannot use as absolutely valid differentiating characters such as are 
afforded by the open or closed eyes of the young at birth, by their 
being clothed in down or naked, by their remaining in the nest or 
not, by their way of feeding themselves or being fed. It is possible 
that the transition from Precoces to Altrices has been governed by 
purely external circumstances, which may still be in action—such, 
for instance, as the nest, being built high above the ground or 
water. There are many Altrices whose whole anatomical structure 
proves them to be more nearly related to certain groups of typical 
Precoces than they are to other Altrices. These circumstances as 
fully explained (Jenaisch. Zettschrift, 1879, p. 385, and Bronn, 
Thierreich, Aves. p. 701) lead to the following divisions of birds in 
regard to their development :— . 
1. Pracoces or Nidifuge—hatched with eyes open; thickly clad in 
down ; able to run at once, or almost at once ; and having such 
an amount of yolk stored in the abdomen as to render them for 
some time more or less independent of other food :—Ratite, 
Crypturi, Galline, Laride, Limicolx, Pteroclidx, Gralle, Anseres, 
Pygopodes. 
2. AvLTRICES or Nidicole— 
a. Lower Nidicole—some hatched with their eyes open, others 
blind ; covered or not with down ; unable to leave the nest ; 
fed by the parents; amount of food-yolk very limited :— 
Spheniscidx, Steganopodes, Tubinares, Herodit, Pelargi. 
