410 



October 20, 1858. 



Dr. Durkee in the Chair. 



Dr. A. A. Gould continued his remarks on the Euro- 

 pean collections of Natural History, giving brief sketches 

 of those of Paris, Florence, Vienna, Munich, Bonn, Am- 

 sterdam, Leyden, and Glasgow. 



Mr. Theodore Lyman read a paper on the forms of birds, the 

 object of which was to show how form, as depending on structure, 

 may be recognized in this class, and may be expressed by meas- 

 urements. He had compared, for this purpose, a hawk and an 

 owl, and a duck and an auk, showing that the form is character- 

 istic in each group, which may therefore be looked upon as a 

 natural family in the animal kingdom. There is no essential 

 difference between the bill and claws of the hawk and owl ; there 

 are, however, very striking differences in the size and position of 

 the eyes, the bulk of the lower body, and in the length of the 

 tarsus. Owls have large, prominent eyes, turned to the front, a 

 body bulky below, and (generally) a very short tarsus ; their 

 abundant plumage is so arranged as to bring out these features ; 

 the feathers of the head make a kind of face, in the midst of 

 which appear a half-buried beak and a pair of round, staring eyes ; 

 the body is large and heavy looking, growing larger below, and 

 apparently ending in a partly concealed pair of feet ; the natural 

 position is bolt upright, on account of the short tarsi and the 

 weight of the body in front. Hawks have eyes of moderate size, 

 rather sunken, and on the sides of the head ; the body is elegant 

 and compact, and the tarsus generally long ; the plumage is 

 commonly shorter and closer ; the ordinary position is with the 

 body standing well up on the legs, and inclined at a small angle 

 from vertical. The owl gives the idea of solemnity and gravity, 

 the hawk that of alertness and vigor, but both share the expres- 

 sion of ferocity. 



In the auks and ducks, both water-birds, the chief elements of 

 difference are the plane of the bill with reference to that of the 



