366 ■ MK. E. DEGEN ON ECDYSIS, 



first. It differs from it in shedding and eventually substituting the quills one by one, 

 sometimes two, even three or four at a time, occasionally but rarely more. Some 

 exceptions to this rule occur amongst the Chenomorp/ue (Schlegel (40), p. 20, l. c, also 

 mentions the Anatince as exceptions), where the juvenile condition of shedding the 

 flight-feathers in greater numbers seems to occasionally recur with the periodical 

 moult. A case of such a seemingly abnormal character has been observed by "Wiese, 

 on an old Crane (" Beitrage zur Ornithologie Pommern's," J. f. O. 1855, iv. Heft, 

 No. IS, p. 515). But, as has been pointed out by Gloger (26), p. 392, when remarking 

 on this case: "These birds have other means of locomotion than flight alone.'' Quite 

 recently I had an opportunity of seeing a like condition in a Moorhen, kindly brought 

 to my notice by Mr. C. H. Grant in the Natural History Museum, who regarded the 

 occurrence as an exceptional one. The fishermen of the lake-entrances and 

 inlets on the south coast of Australia know this fact so well that in the case of 

 the Black Swans (Chenojns atrata), which are so numerous there, they frequently 

 take advantage of the temporary impediment to which the •' Moulter," as the bird is 

 called at this time, is subjected, and amuse themselves by running it down in their 

 sailing-craft — a very exciting sport. 



With regard to perennial moult, Schlegel (40) says, p. 20 : ''6. The order in which 

 the flight-feathers are shed and replaced is that of bilateral symmetry." Beyond this 

 general statement he has nothing further to say with regard to this important factor in 

 the feather-change. The observation that the flight-feathers Avere replaced in an 

 irregular sequence of their order, belongs to Gerbe (23). Although his observations 

 extended to a general comparison only between the Gallince and Passeres, it is note- 

 worthy, nevertheless, to find how greatly he was struck by the peculiarity ot order in 

 which the moult proceeds on the forearm. This order he describes thus: "7°. A 

 I'avaut-bras, la mue chez les Passereaux ue commence generalement que lorsque la 

 cinquieme des primaires vient de tomber. Elle se manifest a la fois sur les deux 

 jjoints extremes du cubitus et prend deux directions qui tendent Tune vers I'autre ^ : d'un 

 c6te elle se poursuit de la premiere de secondaires [cuhitals) ^ a la sixieme inclusive- 

 ment ; de I'autre de la neuvieme ou derniere a la septieme." 



For a considerable extension of our knowledge on this point we are indebted to the 

 researches made by Wittmer Stone (44), who regards the laws and principles which 

 govern ecdysis as, what he rightly terms for the bird, " a ]}hysiological necessity, common 

 to all"^. But in attempting to deal with it in general as he has done, the ground 

 cannot be considered as sufficiently prepared until all the phases are known through 

 which the individual passes. 



' The italics are mine 



