158 



Trowbridge — Interlocking of Emarginate 



Explanation of Table Y and Cm-re* in Fig. 11. 



The measurements in Table V were made on one of the 

 first primary feathers of a Sharp-shinned hawk ; Series 3 by 

 calipers and Series 4 by photography and a measuring machine. 



The primaries of the wing of the same bird as" that from 

 which Series 3 and 4 were taken were later artificially inter- 

 locked and pressed together with constant pressure; then, 

 after having been interlocked for several hours (see fig. 11, 



11 



3. 









































11 





















































































QJ 











































QJ 



5 











































21* 



















































































,-c 











































o 











































2 



















c 













6- 



* 











a 

























T"c 















■3 



_S 



^1 



T3 

















































-4 





— ? 



3 





























*> > 



































































































n 















































5Q 



)00 

 Time in M i nute s 



ISO 



200 



Fig. 11. Series 8 and 4: Eecovery of a web of a first primary feather 

 notched by natural interlocking. Sharp-shinned hawk. Accipiter velox, 

 Series 3 by calipers, Series 4 by photography, see Table V, primary found 

 interlocked. 



Series 5 and 6 : Eecovery of the webs of first primary feathers of the same 

 bird when the feathers were interlocked by artificial interlocking. Series 5 

 interlocked for 2 hours 40 minutes, Series 6 interlocked for 4 hours 10 

 minutes,. measurement by micrometer microscope. 



Series 5 and 6) the feathers were unlocked and the gradual 

 recovery of the web as shown by the decrease in the width of 

 the notch was measured by means of a micrometer microscope. 

 Series 5 was taken seven days after the hawk was killed and 

 Series 6 was taken about one week later. The notches in the 

 webs of the feathers thus artificially made are seen to be less 

 in width than the notches found in the webs of the feathers 

 which were naturally interlocked (Series 3 and 4). The rate 

 of recovery is approximately the same as is also the form of 

 the curves, as in Series 3 and 4. 



