620 Correspondence. [Oct. 



be found to result could one successfully transplant and keep track of birds 

 of migratory species from the northern to the southern hemispheres, or 

 vice versa. The writer's only excuse for calling attention in this ornitholo- 

 gical publication to data bearing directly on mammals only, is that the 

 data also bear indirectly on cognate processes in birds, and should be avail- 

 able for future investigators of migration, etc, 



Very truly, 



W. H. Bergtold. 

 Denver, Colo. 



