长津湖观后感Strix Virginiana. Linn.

They are frequently divided into two great sections; the one, which is by far the most numerous, comprehending[234] all those in which the poison-fangs are wanting, and which are consequently dangerous only in proportion to the extent of their muscular force; and the other consisting of those in which the fangs are present, and the bite of which is accompanied with the pouring out of a venomous secretion. At the head of the first of these divisions rank the Boas, which in the Linnean arrangement comprehended all those snakes, whether venomous or not, whose under surface was covered with narrow transverse plates, and whose tail was destitute of rattle. Later zoologists have, however, confined that appellation to those among the Linnean Boas, which are without poisonous fangs and have claws near the vent, and have regarded as a distinct genus the snakes which in addition to these latter characters have the scales of the under surface of the tail so arranged as to form two distinct rows. To the latter, which inh

长津湖观后感 

Linn?us united under the common title of Pelicans, the Cormorants, the Boobies, and several other birds, which differ from the typical species of the genus by many important characters, the chief point of agreement between them consisting in the form and extent of the membrane which unites the toes. The Linnean group has subsequently been raised to the rank of a family, and its component parts form several distinct genera, that which comprehends the true Pelicans, the genus Onocrotalus of Brisson, being characterized as follows. Their bill is of very great length, straight, broad, flattened above, and terminated by a slight hook; the lower mandible consists of two lateral branches, united at the point, and having interposed between them a membranous pouch capable of very great dilatation; their four toes are all enveloped to the very apex in the common membrane; their legs are short, strong, and maintain the body in a state of equilibrium, their lower part being entirely destitute of feathers.
frequently turns completely white, a change which also takes place in many other animals inhabiting the polar regions.