EXTERNAL JfARES OF THE CORM()RA:jfT. 20& 



lining. Microscopical examination — made in the first instance 

 by my friend Mr. H. M. Bernard, and afterwards confirmed 

 by myself — showed that the lumen of the " plug " was com- 

 pletely blocked up by delamination of fragineats of the horny 

 layers from its inner surface, A bristle passed down the narial 

 aperture, now throwa open by the removal of the plug, made 

 its exit as usual at the posterior nares . 



The nasal cavity is a small chamber devoid of any trace of 

 turbinal folds, and more or less imperfectly divided into anterior 

 and posterior moities by a vertical transverse partitioa depend- 

 ing from the roof into the chamber, the ventral border of the 

 partition being free. 



In the embryo (Sg. 2) the narial aperture lies within the 

 rhinothecal groove, much as described by Ewart in the adult, 

 and is still open. It is interesting to note that the oblique 

 groove for this aperture in the adult is not yet indicated, neither 

 is the segmented portion of the posterior end of the gnathotheca, 

 so marked in the Grannets though comparatively slightly developed 

 in the Cormorants (fig. 1, y'). 



Mr. F. A. Lucas in ' The Auk ' (vol. xiv. p. 87) has an interest- 

 ing note on the external nares of the embryo and nestling 

 Cormorant. He finds the nostrils still open in the oldest of 

 the nestlings in his collection; the age of these he estimates at 

 28 days. He considers " that the external nostrils close about 

 the time the young Cormorants take to the water and begin to 

 feed themselves.' 



LINN. JOURN. ZOOLOGY, VOL. XXVIT. 16 



