94 BIRDS OF LA PLATA 



Heron would seem a fit subject for them^ and in the 

 course of my rambles I have picked up many in- 

 dividuals apparently perishing from inanition. I do 

 not wish to insinuate a belief that this immunity &om 

 vermin is due to the pectinated claw ; for though the 

 bird does scratch and clean itself with the claw it 

 could never rid the entire plumage from vermin by 

 this organ, which is as ill adapted for such a purpose 

 as for " giving a firmer hold on its slippery prey." 



The Spoonbill has also the serration, and is, unlike 

 the Heron, an active vigorous bird and usually fat ; 

 yet it is much troubled with parasites, and I have 

 found birds too weak to fly and literally swarming 

 with them. 



I merely wish to call the attention of ornitholo- 

 gists to the fact that in the region where I have 

 observed Herons they are exempt in a remarkable 

 degree from external parasites. 



Much has also been said about certain patches of 

 dense, clammy, yellowish down under the loose 

 plumage of Herons. These curious appendages may 

 be just as useless to the bird as the tuft of hair on 

 its breast is to the Turkey-cock ; but there are more 

 probabilities the other way, and it may yet be dis- 

 covered that they are very necessary to its well-being. 

 Perhaps these clammy feathers contain a secretion 

 fatal to the vermin by which birds of sedentary 

 habits are so much afflicted, and from which Herons 

 appear to be so strangely free. They may even be 

 the seat of that mysterious phosphorescent light 

 which some one has affirmed emanates from the 



