386 MR. E. DEGEN ON ECDYSIS. 



During the first total feather-change in the young bird, and to a great extent also 

 in that of the following season, all the feathers constituting this series make their 

 appearance simultaneously and parallel with the dorsal row of medians 1-10, witliout 

 the ultimate division into the metacarpal and the digital area, which is so character- 

 istic for subsequent moults. In this case, however, the synchronous development 

 with their equivalents of the dorsal series is a perfect one in their entirety. Partly in 

 the second, but wholly so in the third season, the transitory step from the one mode 

 to the other is effected by an intermediary stage. This consists in the inferior row 

 moulting in arrear of the dorsal one still, while yet adhering to the non-deciduous form 

 of renewal by means of a gradual supply of the feathers which begins with covert 1 

 (the innermost) and ends with 10 (the outermost). The dorsal row has meanwhile 

 already acquired, either on one side only or symmetrically from both wings, the 

 perennial or deciduous style above mentioned of the areal form of moult. 



Nos. 7, 8, 11, 12 (see also diagrams for these. Table V. figs. 3 & 4), and also 13 

 are examples of specimens of either one or the other of these transitory cases. The 

 fully adult mode of moult, in which the ventral equivalents are renewed in absolute 

 synchronism with the dorsals, is reached only when the bird attains the positively 

 adult stage, and not before the 4th annual moult. 



An approximate key to the various phases of the relative development between the 

 dorsal and ventral rows is appended at the close of the description for the whole 

 of these series (see p. 390). 



Cubital Portion. — Bilateral symmetry, as we have seen it to exist mainly for the 

 hand-portion of the wing, is not nearly so pronounced a feature on the forearm for 

 this row of feathers. Out of 10 specimens showing this phase of the moult there are 

 o which show cases of asymmetry in the corresponding portions of the two wings, 

 as the following analysis of these specimens shows : — 



Symmetrical Development. 

 Males. Old : Nos. 17, 20, 24, 25 ... . 4 



„ Young — 



Females. Old — 



Young: Nos. 14, 19, 23 3 



Total . , 7 



Asymmetrical Levelopment. 



Males. Old : No. 1 1 



„ Young : No. 4 1 



Females. Old — 



„ Young : No. 12 1 



Total . . 3 



Grand total .... 10 



