172 To the River Plate and Back 



suggested that they might have been planted. In the 

 canals and bayous there were abundant growths of 

 aquatic plants, among them a natant Pontederia. 



Birds were not as numerous as I had expected to find 

 them. A few herons were seen on the wing. Cor- 

 morants (Phalacrocorax brasilianus) abounded. They 

 hardly took the trouble to get out of the way of the 

 vessel as it came toward them. Sometimes they rose 

 and made a short flight, but frequently only dove to 

 the right or the left and came up again a few feet away. 

 The birds seem to be silent, and I never heard them 

 utter any cry, but W. H. Hudson, who has written 

 most charmingly about the birds of Argentina, says: 

 "When many individuals congregate to roost on the 

 branches of a dead tree overhanging the water they 

 keep up a concert of deep, harsh, powerful notes all 

 night long, which would cause any person not ac- 

 quainted with their language to imagine that numerous 

 pigs or peccaries were moving about with incessant 

 gruntings in his neighborhood. ' 



On the wider reaches of the river we saw a few gulls 

 (Larus maculipennis) . The gaviotas, as the natives 

 call them, have the habit, which I have observed to 

 belong also to the gulls of Scotland and Scandinavia, 

 of following the plowman in the furrows to pick up 

 grubs and worms. In Argentina they are viewed with 

 favor by the country-folk. Hudson says: 



If the weather is dry the gulls disappear altogether; and 

 if grasshoppers become abundant the country people wish 

 for rain to bring the gulls. When it rains, then the birds 

 quickly appear, literally from the clouds, and often in such 

 numbers as to free the earth from the plague of devastating 

 insects. It is a fine and welcome sight to see a white cloud 

 of birds settle on the afflicted district; and at such times 



