lt)0 Jeffries o>i tJie Primaries of Birds. 



little feathers lie one over the other and, owing to their small size, 

 apparently on the shaft of the first developed primary. The same 

 condition is found in the young of Goniaphea ludoviciana, and 

 Sialia sialis. Passer don/esfiea differs in that the first primary 

 is in due proportion to the first covert. 



This proves that the ''first little feather" is nothing but the 

 covert to the first developed primary and that the " second little 

 feather " is an undeveloped primary. 



There is no room for doubt about the homologies of the pa- 

 pilla', and the feathers are nothing but parts of the papilla-. The 

 second and subsequent sets of feathers are developed from buds 

 of the original papillae, much after the manner of teeth, anil 

 hence are equally determinate with the original papilla' from 

 which they spring. 



If we examine a ten-primaried Oscinine bird we find the same 

 condition of things as in the nine-primaried. except that the 

 first primary papilla is of good si/e. Of this condition of things 

 the fledglings of Troglodytes aedon and Mimus caroUnensis 

 are good examples. So the formula for a nine-primaried and a 

 ten-primaried Oscinine bird is the same. The number of feathers 

 can be represented as follows. •• ab." standing for aborted, and a 

 minus sign indicating a feather belonging to a series of the fore- 

 arm beyond the carpus : 



Melospiza melodia: Pr.. i ab.. 2 — 10; pr. c. 2 — 10. 3rd row. 

 7. Sec, 9, sec. c, — 1,2 — 11, 3rd row. 8. 



Mimus caroUnensis: Pr. 1 — 10, pr. c. 2 — 10. 3rd row. 7. 

 Sec. 9, sec c, — 1. 2 — 11. 3rd row. 1 — 6. 7 — 8 small. 



To this rule Corvus americanus forms an exception, since it 

 seems to have ten primary coverts. 



Passing to the Claviateres, the King Bird ( 7V rain/ its car- 

 oUnensis)^ will be taken as an example. Here the fore-arm 

 remains nearly the same, even in respect to the auxilliary feathers. 

 but in the hand we find a first covert beyond the first primary and 

 another corresponding feather added to the third row . .So the 

 formula for Tyrannus caroUnensis is : Pr.. 10. pr. c. 10. 3rd row. 

 S ; sec, 9, sec. c. 10 — 1. 3rd row, 9. 



[n the fledgling of Chcetura pelasgica we find the following 

 formula: Pr.. 10. pr., c 10. 3rd row. 8, sec. 9. sec c. 10 — j , 

 3rd row 7. Besides these there are several more rows. 



In the adult Trochilus colubris there are ten primaries and 



