The Making of Species 



of a young male Shoveler (Spatula clypeata), " in 

 which the metallic colour on the head first showed 

 itself on the post-orbital and auricular pcecilo- 

 meres, gradually meeting and joining up across 

 the head with the crown and occipital pcecilo- 

 meres, and then finally spreading forwards. And 

 it may be well to note that the joining up of the 

 auricular and post-orbital pcecilomeres formed 

 a metallic patch similar in size and position to 

 that found in the male Teal (Querquedula crecca\ 

 and, further, in the last stage, when the whole 

 head, except the portion round the beak, was 

 metallic, the markings are similar to those found 

 permanently in the hen Scaup {Fuligula marila). 



Now, these resemblances taking place in the 

 normal pure-bred wild shoveler, the question of 

 reversion does not come in, and no one would 

 suppose these resemblances due to anything 

 more than transitional variation, and it is the 

 object of this portion of the paper to show that 

 variation in colour follows along definite lines." 



Mr Bonhote continues : " As a further illus- 

 tration of how widely spread these lines are 

 throughout the mammalian and avian kingdoms, 

 we may note the assumption of the brown head 

 in the case of the Black-headed Gull (Larus 

 ridibundus\ which invariably follows each year 

 on lines similar to those related in the case of 

 the shoveler, and . . . the method by which, on 

 the approach of winter, the stoat assumes his 



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