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 (fudzgula 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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