310 Miscellaneous Facts in Zoology. 
had placed himself, who, from his size, seemed to be the 
master of the herd. The traveller now observed thata fam- 
ished wolf was attempting by various manceuyres to seize 
one of the pigs in the middle; but wherever he made an 
attack, the huge boar at the apex of the cone presented him- 
sel{—the hogs dexterously arranging themselves on each 
side of him, so as to preserve the position of defence just 
mentioned. ‘The attention of the traveller was for a mo- 
ment withdrawn, and, upon turning to view the combatants, 
he was surprised to find the herd of swine dispersed, and 
the wolf no longer to be seen. On riding up to the spot, 
the wolf was discovered dead. on the ground, a rent being 
made in his side, more than a foot in length—the boar hay- 
ing, no doubt, seized a favourable opportunity, and with a 
sudden plunge dispatched his adversary with his formidable 
tusks. : 
It is a little remarkable that the ancient Romans, among 
the various methods they devised for drawing up their ar- 
mies in battle, had one exactly resembling the position as- 
sumed by the swine above mentioned. The mode of attack 
they called the Cuneus, or Caput porcinum. 
Blue- Yellow Bird.—Fringilla tristis. 
To those but little acquainted with Natural History, the 
assertion that a white black bird (oriolus Pheeniceus) or a 
black swan (Anas Atrata) are animals really in existence, 
appears too paradoxical for belief. Black swans, however, 
are found in New Holland and some other places, possess- 
ing all the graceful atitudes of the European species ; and 
‘white black birds or albinos, are of no very uncommon oc- 
currence. 
I have observed another anomaly among the feathered 
tribe no less striking. A bird of precisely the same size, 
habits, and general appearance with our common yellow 
bird, (Fringilla tristis) associating with it, and differing 
only in colour—this being of a dark indigo in the places 
where the male (F. tristis) is yellow; the black bands on 
the wings, and the spot on the head, were the same in both. 
The following hints are offered by way of theory to ex- 
plain these anomalies :—If there be any truth in the opinion 
entertained by many, that the imagination of the parent, or 
