Cuass Il. BITTERN HERON. 
of notes; the one croaking, when it is disturb- 
ed; the other bellowing, which it commences 
in the spring and ends in autumn. Mr. /V1l- 
lughby says, that in the latter season it soars 
into the air with a spiral ascent to a great height, 
making at the same time a singular noise. From 
the first observation, we believe this to be the 
species of heron that Virgil alludes to among 
the birds that forbode a tempest, 
In sicco ludunt fulice ; notasque paludes 
Deserit, atque altam supra volat Ardea nubem *. 
For the antients mention three kinds ft; the 
Leucon, or white heron; the Pellos, supposed 
to be the common sort; and the Asferias, or 
bittern; which seems to have acquired that 
name from this circumstance of its aspiring 
flight, as it were attempting, at certain seasons, 
the very stars; though at other times its motion 
was so dull, as to merit the epithet of lazy. 
Some commentators have supposed this to 
have been the Zaurus of Pliny ; but as he has 
expressly declared that to be a small bird, re- 
markable for imitating the lowing of oxen, we 
must deny the explanation, and wait for the 
discovery of the Roman naturalist’s animal from 
* Georg. i. 363.— 
4 Arist. hist. an. 1006. Plin. lib. x..c. 60. 
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