26 



Zoologia: N. Y. Zoological Society. 



[Vol. I 



moult this general darkening is much more noticeable, and cor- 

 related with it there is considerable reduction of the rufous 

 on the primaries and on the lining of the wings. The greater 

 wing coverts are very light, the outer vanes appearing almost 

 pure white in contrast with the adjacent areas of black and dark 

 brown. 



Although the considerable individual variation, as shown in 

 greater or less reaction to the humid atmosphere, is very no- 

 ticeable even in the few specimens upon which I have been able 

 to experiment, yet the general average appearance of this moult 

 under these conditions is not distinguishable from that of a wild 

 bird in the typical plumage of Scardafella ridgtvayi. 



The rose or lilac ground color of the upper anterior part of 

 the plumage remains unchanged, until, in succeeding moults, it 

 is totally obscured by the encroaching melanin pigment ; the white 

 of the lower breast remains clear white to the last ; the suffusion 

 of pink over the breast loses none of its intensity until completely 

 concealed by the black. In the final stage, attained in the fourth 

 or fifth moults, the chestnut on all the primaries has completely 

 disappeared; the breast feathers, secondaries and even the 

 greater coverts have lost all trace of white, although, as we no- 

 ticed above, the coverts had become noticeably whiter at the sec- 

 ond moult. The last white to remain is a spattering upon the 

 longest under tail coverts and upon the three outer rectrices. 



TABLE V. 

 Primary Change of Coloration Area of Scardafella under Humidity. 



Outer Right Primary 



Second Right Primary... 



Third Right Primary 



Sixth or Outer Rectrices. 

 Fifth Rectrices 



At End of Third 



Annual Month, 



Jan. 28 



38 



37.4 



36 



32.8 



24 



First Induced 



Monthly Renewal 



Feb. 25 



37.: 

 38 



Second Induced 



Monthly Renewal 



Mar. 27 



41.6 

 39.2 

 39.2 

 33.3 

 29.4 



Average 



Increase of 



Area 



3.6 

 1.8 

 3.2 

 .5 

 5.4 



Table V gives the average areas of the black on the primary 

 tips and of the white on the three outer pairs of rectrices of a bird 

 from Mexico which, under experimentation, had completed the 

 normal third annual moult. It will be seen that the area of the 

 black outer primary patch is slightly larger than in the wild 

 Brazilian bird (Table I). The white on the outer rectrice of 



