340 BRITISH BIRDS. [vol. vi. 



Cassowaries where the old feathers adhere for a certain period 

 to the tips of the feathers ^\•hich succeed them. The calamus 

 of the " ejected " feather eventually dries up and the feather 

 is shed. It is probable that the distal feather under con- 

 sideration A\'ould have been shed in a similar way in the 

 ordinary course of events. 



A precisely similar case is that of the feather (one of the 

 innermost secondaries of a Knot) which was exhibited by 

 ]Mr. J. L. Bonhote at a meeting of the Zoological Society 

 of London {P.Z.S. 1906, p. 901). In this specimen the 

 summer-feather had not been shed but was continuous Avith 

 the new autumn-feather. The summer-feather was shorter 

 than in the normal condition and, Mr. Bonhote believed, 

 was possibly not full groAMi when the autumn-moult 

 commenced. Mr. Bonhote is of the opinion that the 

 abnormality may have been caused by the replacement of 

 an injured feather by a new feather, the growth of ■which 

 was cut short by the intervention of the autumn-moult and 

 the consequent activity of the follicle which, instead of 

 completing the half-gro\Mi feather, began to form another 

 feather, the stem of Avhich Avas continuous with that of the 

 feather already full groA\Ti. 



The small size of the distal feather in the pigeon cannot be 

 due to the fact that it Avas only partially groAMi, as it has a 

 distinct calamus, but it may have been due to lack of 

 nutrition or some other physiological cause, such as the los? 

 of a feather owing to some injury between successive moults, 

 and a not entirely successful attempt on the part of the 

 follicle to replace the feather. 



With the exception of the Knot's feather already referred 

 to, there is apparently no other recorded instance of a similar 

 kind. 



