Letlera, Extracts, and Notes. 191 



(e) Kestrel. A clutch of 6; four eggs normal, one cream- 

 coloured with a few minute brown dots scattered over it, the 

 sixth egg showing a pure white ground-colour at the larger 

 end, the lower portion being blotched with red. 



(/) Sparrow-Hawk. A clutch of 6, five of the eggs 

 showing only underlying violet markings^ the sixth heavily 

 blotched with red surface-pigment. 



Also a single egg of the same species, so heavily marked 

 all over with red, that it might be mistaken for a Kestrel's, 

 but for the blue ground-colour showing through. 



Experiments on Homing. — Prof. J. B. Watson and Dr. K. 

 S. Lashley* have recently made some important experiments 

 at Bird Key, in the Tortugas, on the homing capacity of the 

 Noddy Tern {Anous stolidus) and the Sooty Tern {Sterna fuli- 

 ginusa), which breed there in large numbers. The island is 

 peculiarly suitable for the purpose, since it marks the 

 northern limit of the migration of these two tropical Terns 

 (so that if the birds are experimentally transported further 

 north, they find themselves in regions which they have not 

 previously visited); moreover, on the westward side there 

 is only the open water of the Gulf of Mexico until the 

 shore-line of Texas is reached, Galveston being 855 statute 

 miles distant. " This strip of open water proves a mag- 

 nificent route for homing experiments.'' The authors 

 caught Terns at their nesting-places, put individual marks 

 of paint on their head and neck, tied a small tag recording 

 the date, locality, and marking round the neck, fixed a 

 larger duplicate tag beside the nest, transported the birds 

 in large cages to a distance, liberated them, and watched 

 for their return. The general result is of great interest : — 

 " The Noddy and Sooty Terns can return from distances up 

 to 1000 miles in the absence of all landmarks, at least so 

 far as the term landmark is understood at present." 



* Papers from the Department of Marine Biology of the Carnegie 

 Institution at "Washington. Vol. vii., "Homing and Related Activitie.-^ 

 of Birds." By J. B. Watson and K. S. Lashley. Pp. 1-104+7 plates + 

 9 Hg*. (Washington : The Carnegie Institution, 1915.) 



