G98 Mr. P. R. Lowe on the 



Coll.), 76 mm., 71 mm., 71 mm., 69 mm., 68 mm., and 

 63 mm. in six examples contained in Lord Rothschild's 

 collection^; whereas the same measurements in the skull 

 of the present existing C. pusilla works out at 54 mm. 



Practically similar measurements to this last (51 mm. 

 and 54'5 mm.) were noted in the skulls of two examples of 

 C. pusilla found subfossil in the same sand-bank as con- 

 tained the above subfossil remains of C chathamica. 

 Variation, as is well known, is very prone to run amok in 

 the case of flightless birds on isolated islands where enemies 

 are few, so that the varying measurements in C. chathamica 

 might be taken to indicate toleration on the part of natural 

 selection. On the other hand, it is just possible that they 

 might be taken as indicative of a gradual grading of the one 

 form into the other, so that in C. pusilla of the present day 

 we have a direct lineal descendant of C. chathamica — or, in a 

 word, that the two forms represent in reality one species, 

 exhibiting a diminishing and continuous series of gradations. 

 Such, however, does not necessarily follow, and it may be 

 pointed out that in the Chatham group two distinct species 

 of Cabalus are known to have existed, not to mention other 

 forms. 



The point seems to me to be worth consideration in con- 

 nection with the question whether the normal process of 

 evolution is a gradual or a discontinuous process. 



At the present day C. pusilla has so far lost the power of 

 flight that it can be easily knocked down by a stick, although 

 when it first rises it is said to exhibit a feeble imitation of 

 the twists and turns of its more northern congeners before 

 it sinks to the ground some twenty yards from the spot 

 where it rose. Other points in connection with the peculi- 

 arities of this interesting '' Snipe " are as follows : — its eggs 

 are not Gallinagine in either shape or colouring, the shape 

 being a compromise between the typical Gallinagine and the 

 typical Rusticoline form and the colouring being reminiscent 



* For permission to examine these fossil remains from the Chatham 

 Islands now preserved in the Tring Museum I am greatly indebted to 

 Lord Rothschild. 



