NESTLING BIRDS AND WHAT THEY TEACH 255 



longitudinal stripes. Nowhere are these stripes seen to better 

 perfection than in the young of the Emu. Here, in the very- 

 young bird, we find a long, thin, white stripe extending from 

 the head down the back of the neck, and tail wards along the 

 back on either side of the middle line. Below the trunk-stripe 

 a second occurs, but towards the end of the nestling period it is 

 interesting to notice these stripes appear to increase in number. 

 The second, inferior trunk-stripe of the newly hatched bird 

 extends forward to join the neck-stripe just described; and 

 beneath the second, now elongated stripe, a third appears, and 

 this runs upwards to form a second neck-stripe, mnning parallel 

 with the first ; below this third a fourth stripe appears ; this 

 extends from the end of the tibia, upwards and forwards along 

 the flanks, terminating at the base of the neck. The continuous 

 neck-stripe. No. i, 'breaks up at the base of the skull into a 

 number of dots in the older birds. In the very early stages 

 the legs bear curious mottled markings, but these rapidly 

 vanish. 



In the young Cassowary (p. 258), at an age roughly corre- 

 sponding to the second stage of the Emu, only the faintest traces 

 of spots on the head and neck are traceable. On the trunk we 

 find five white bands sharply defined, and set off by a darker 

 ground than in the Emu. The fifth corresponds to the leg and 

 flank stripe of the Emu, but is shorter. 



In the nestling Rhea stripes also occur, but these are less 

 conspicuous and fewer in number than those of the genera just 

 described. The neck-stripes are obsolete. 



The nestling Ostrich appears to differ from the other 

 "Ratites" in having a uniform coloration. The trunk, it will 

 be remembered, presents a curiously grizzled appearance, and 

 this is due to the fact that the tips of the rami of each down 

 feather are produced into long ribbon-like horny processes. 

 But there can be little doubt but that this peculiar structural 

 modification of the down feathers is comparatively recent, since, 

 though these no longer display a pattern, the down feathers of 

 the neck agree precisely with those of the Emu, in that they 

 are coloured so as to form very strongly marked longitudinal 

 stripes down the back of the neck, while along the front of the 

 neck and the sides of the head these stripes give place to rows 

 of dots. 



