666 



DR. J. C. MOTTRAM ON SECONDARY 



a severe bite can only be given when the finger is seized far back 

 in the bill : at the tip the leverage against the jaw-muscles must 

 be very great, and, unlike most long bills, they are unsuitable for 

 stabbing. 



Table III. 



Notes. — Compiled from Monographs on the Biicerotidse by D. G. Elliot and the 

 RamphastidfB by J. Gould. 

 a. = sexes alike; v.sl.d.=sexes very slightly different; sl.d. = slightly different; 

 so.d.=some difference; d. = different; v.d. (used in other tables)=very 

 different. 



If, instead of considering birds from the point of view- of 

 defence we classify them according to their offensive powers, 

 the same conclusion results. Offensive powers are divided 

 according as to whether the birds' diet consists of vertebrates, 

 small vertebrates, invertebrates, or vegetable matter, as set out 

 in Table III. a. 



Table III. a. (Food of Birds.) 



Notes. — Compiled from F. Finn's ' The World's Birds.' 



Numbers at column headings refer to secondary sex characters as before. 

 Keference Nos. :— 1 vert. 1, 2, 13, 18, 32, 35, 36, 43 : 2 vert. 7, 12, 20, 27 : 1 vert. 

 & invert. 4, 8, 22, 25, 40, 44, 45 : 2 vert. & invert. 15, 26, 31 : 3 vert. & 

 invert. 21, 28 : 1 vert. & veg. 6, 9, 17, 28, 29, 30, 46, 48 : 2 vert. & veg. 3, 

 10, 33, 37, 39, 42, 50 : 3 vert. & veg. 11, 23, 47 : 4 vert. & veg. 5, 14, 16, 19, 

 24, 34, 41, 49, 



Further, certain birds for other reasons are especially free 

 from enemies. Diving-birds have always a safe refuge at hand, 



