THE AMERICAN MUSEUM JOURNAL 



suggests a malformation, will then be found to be closely related 

 to the bird's manner of feeding, which is to drop the elongated 

 lower mandible slightly below the surface as it skims rapidly 

 over the water. In this way the bird gathers various forms of 

 aquatic life for food. 



In a similar manner, observation shows that the singular^ 

 re-curved or upturned bill of the Avocet (No. 3) is used to find 

 food on the bottom in shallow water. When feeding, the bird 

 swings the head from side to side through an arc of about 50°, 

 the convexity of the lower mandible just grazing the mud or 

 sand, while the delicate, pointed tip of the bill is turned up out 

 of harm's way. Similarly the lamellirostral or platy bill of the 

 Mallard (No. 2), the serrate or saw bill of the Merganser (No. 4), 

 the spatulate bill of the Spoonbill (No. 7), and the tenuirostral 

 or slender needle-like bill of the Hummingbird, indeed the bills 

 of all birds, will be found to be related to the character of the 

 food of the bird in question or to the manner of obtaining it. 



On studying the feet, wings and tails, a similar close con- 

 nection between form and function is seen to exist ; and, while it 

 is necessary so to describe and name a form that the terms em- 

 ployed become a part of the exact language of science, termin- 

 ology is only a means to an end, and should indicate to us the 

 cause of the widely different types of structure which are en- 

 countered in nature and of which only a few are illustrated in 

 this new exhibit. f. m. c. 



MEXICAN CODICES. 



§|N this Journal for October, 1901, there is a brief 

 notice of the exhibition of the reproductions of 

 the several ancient ]\Iexican manuscripts for 

 which the Museum is indebted to the Duke of 

 Loubat. To this interesting exhibit tliere has 

 recently been added, as a gift from the Peabody Museum of Har- 

 vard University, a reproduction of a beautiful example of ancient 

 Mexican picture-writing. The re-discovery of this codex is due 

 to the indefatigable researches of Mrs. Zelia Nuttall, in whose 

 honor it has been named the Codex Nuttall by the Peabody 



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