MR. E. DEGEN ON ECDYSIS. 367 



VI. — '• Orders op the Moult " in Gymnoehixa tibicen. 



A. Flight-feathers or Pennce alares ^= Remiges primores plus 

 Bemiges cuhitales (Sundevall). 



The relative lengths of the flight-feathers on the manus are in the order below from 

 left (the longest) to right (the shortest), thus: — 



7—6—8—5—9—4—3—2—1—10. 



The manner in which the remiges make their appearance is regulated by a definite order 

 in both portions of the wing. As might have been expected, the bilateral symmetry 

 assigned for the individual {cf. Schlegel, 40, p. 21) is not strictly observed. But there 

 is at no time any considerable departure from the broad principle. Besides this general 

 bilateral form of symmetry, there is one existing also for the two portions of each Aving 

 inter se, viz. the hand and the forearm. It is present during the earliest stage of the 

 moult in the case of primaries I. and II. and secondaries VIII. and IX., the remiges 

 corresponding with each other for moulting first, as represented by specimen No. 1. 



DiAGR. A (stage a and h). (Lettered on Plate XXXVI. a, b and a', V respectively.) 

 The fully adult specimen No. 1 (left and right wing) showed this earliest stage 

 remarkably well ; younger ones not complying with the rule so exactly, as No. 2 

 proves, and also the following one, shot on the same date, mostly young birds. 



DiAGR. B (stage c, d, e). (Plate XXXVI.) 



The parti-lateral symmetry of the first stage becomes soon disturbed by the appear- 

 ance, in rapid succession, of primaries III., IV., and V., lettered in the Table c, d, 

 and e respectively, these having no equivalent renewal on the cubitus ^. Four specimens 

 show this arrangement remarkably well, of which No. 4, a very young male, does so in 

 part only. The diagram represents specimen No. 3. 



DiAGR. C (stage/). (Plate XXXVI.) 



The next stage, that of/, which comprises the replacement of primary VI., is a 

 particularly interesting one, insomuch as it marks the restoration of the parti-lateral 

 symmetry by an almost simultaneous development of three secondary remiges. These 

 are cubital remiges I. or/', X. or/", and VII. or /'". Their synchronous appearance 

 therefore is a competisation for primaries 1 III., IV., and V. It is marked best in the 

 left wing of specimen No. 7, Plate XXXVI. , as shown in the diagram C, which repre- 

 sents this third stage or that of/ and its equivalents. This also explains the reason 

 why these remiges are equivaluated /',/", and/'" respectively (the dashes representing 



' The italics are mine. 



