I1IO THAYER, Banner Mark Theory. Aut 
blers, Shrikes, Meadowlarks and Nuthatches, are a few Ameri- 
can examples of birds which show in flight more or less additional 
white or bright pattern on their upper sides, which disappears 
when they close tail and wings. Of course the irregular motion 
of flight or running brings also into the light the borders of their 
white underside (which, contrary to Mr. Thompson, is an essen- 
tial part of their protective coloration when at rest, unless they are 
squatting), making it aid, for the moment, their conspicuousness. 
Now, as to the patterns on the wnder side of wings of soaring 
birds, and of such species as Plover, which hold their wings 
stretched upward after alighting; the theory that they are first 
of all for mutual recognition seems disproved by the foregoing 
arguments, and we should seek other explanations of their exis- 
tence in cases where, as I have pointed out, any good observer 
can recognize the species by its whole ‘cut’ at a far greater 
height than one could see the pattern, and if this be true of 
even human observers, how caz birds need them for the recog- 
nition of each other? Also, as to Plover, it does not seem 
probable that after being visible and recognizable in flight they 
should so elaborately raise their wings after alighting for no other 
reason than the small added recognition-aid they thereby give to 
their neighbors, especially since their under wing pattern is of 
course invisible to’this neighbor (unless Plovers’ eyes be some- 
thing quite beyond our imagination) until they are so near each 
other that mutual recognition is inevitable without aid of badges. 
All these under-wing patterns, without any exception that I can 
recall, belong to birds that live among backgrounds of similar 
patterns. They are found on birds that live more or less amidst 
vegetation, which is the same as saying where their background 
abounds in the nearly parallel lines of grass, reed, or tree stems. 
They are most lacking on ocean birds which have no such back 
ground, passing their lives between bare ocean and bare cliffs. 
These patterns, crossing the main form as they do, belong in 
appearance to the great class of cross-markings, which in the 
tiger and many smaller cats, in the zebra, and in many snakes, 
as well as on many female birds, especially of the Gallina, such 
as the Capercaillie, Blackcock and Prairie-Hen and countless 
other members of the animal kingdom, unmistakably codperate 
