31 



rules. The evidence regarding many diving birds is similar to 

 that obtained in respect to Water Ouzels. One observer sees 

 the Ouzel or Dipper walking on the bottom with closed wings. 

 Another sees it running there with wings raised, slightly ex- 

 tended and held stiffly "to keep it down." Another reports 

 that it flies under water with wings alone, while still another 

 avers that it uses both wings and feet in swimming beneath 

 the surface. There seems to be even greater diversity in the 

 activities of the diving birds. They swim beneath the surface 

 with wings tightly closed, or raised and held loosely, or held 

 close to the body and used in either quick or slow strokes, or 

 well extended, or partially extended, or not extended at all, 

 but merely raised and beating. The carpal joint is not used in 

 some cases or at some times, and is employed in others. The 

 wings sometimes keep time with the feet, whether both feet 

 strike together or are used alternately, but sometimes the wing- 

 strokes are faster than those of the feet, and sometimes the feet 

 are used more rapidly than the wings, while at other times the 

 feet are extended behind and used apparently in steering. In 

 fact, the birds do just as they please, exactly as would a man 

 in diving and swimming. Apparently in pursuing swift fishes 

 or other birds, or in escaping from man, sharks or any other 

 swift or powerful enemies, birds use both feet and wings to 

 make great speed, and only because they can swim faster in 

 that way than in any other. 



Grebes in the shallow marshes in which they breed, where 

 under water they have little use for the wings which would be 

 more or less impeded by vegetation, and where often there are 

 no fish for them to pursue, very likely often depend on foot 

 power alone, but when they or other diving birds need the 

 wings, or care, for any reason, to employ them beneath the 

 surface, they use them as a matter of course. 



For observational purposes the field ornithologist needs two 

 structures that have never yet been employed in his work. 

 First, a watch tower from which he can observe the habits of 

 marsh birds, and the under-water activities of birds in sloughs 

 and shallow ponds; and second, a submarine boat with windows 

 of heavy glass, from which he can watch the deep-water 

 activities of the diving birds. Of the deep-water movements of 



