332 Mr. H. F. WitlierLy on a CoUeding [Ibis, 



plumage (say two or three months after hatching), and in 

 some cases even when it attains its juvenile plumacre, ten 

 days or so after hatching. Beebe's experiments, on the other 

 hand, show that the change in the individual is gradual; and 

 this may be so in certain birds in a state of nature, but in 

 such cases the variation among individuals, according to 

 their age, would be so great that we should certainly not 

 accept the differences as sufficiently constant to constitute a 

 good form. To make my meaning clearer, the Bermuda 

 Goldfinch must have shown its distinctive characters in the 

 very first brood hatched in the island if Dr. Lowe's explan- 

 ation is to be accepted. If, on the other hand, the whole 

 race, as apart from individuals, has changed gradually, then 

 surely this must have been due to something which was 

 transmissible. 



In the following list a dagger mark is affixed to those 

 birds which we identified but did not obtain. 



tCorvus corax. 



Ravens were seen or heard nearly every day, but they were 

 not plentiful. I have seen no skins from north Spain or 

 Portugal, so cannot say if they belong to the form Uspanus, 

 which inhabits south Spain. 



Corvus corone corone L. 



Common and usually in family parties. One obtained is 

 exactly like typical birds. 



Garrulus glandarius fasciatus Brehm. 



Garrulus glandarius Lleinschmidti Hartert, Vug. pal. F. 



i. p. 30. 



Jays were common in all the woods. Six obtained agree 

 with this form, as do Portuguese birds. Although not a 

 very distinct form, it is decidedly darker on the upper-parts 

 in a series than the typical bird, has usually a well-defined 

 dark (blackish) upper-breast, broad streaks on the crown, 

 and a thick and deep bill. These characters as a ivhole. 

 differentiate it well. The wings of a series from Spain 

 and Portugal measure : 9 males 176-189, 10 females 



