Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 25, 2025
The heart of fishes may be called a venous heart, since it only receives venous blood, which passes thence to the gills, while that of crustaceans is an arterial heart. It receives the blood directly it leaves the respiratory organ, and sends it, not into one aorta, but into several arteries, which set out at once, each in its own direction, to nourish the various quarters of the body.
They hardly knew why they were going, and San Miniato almost regretted having persuaded them. Doubtless the crabs were numerous along the rocky shore and they would catch hundreds of them before midnight. Doubtless also, the said crustaceans would be very good to eat on the following day.
You recollect that canal of the liver which I was afraid to tell you the name of because it was so ugly? Well, this is that formidable name! Now that you have swallowed so many others, you must be strong enough to digest this. No chyliferous vessels have been found in crustaceans, whence one may conclude that the chyle leaves the intestine by oozing from it, just as it does in insects.
It is very remarkable, that, while the tail establishes this creature among the vertebrata and the fishes, its mouth has been opened vertically, like those of the crustaceans, but which is contrary to the mode of vertebrata generally. This seems a pretty strong mark of the link character of the coccosteus between these two great departments of the animal kingdom.
These beds are crowded with the remains of insects, small fish, and crustaceans, with occasional marine shells. One band in Gloucestershire, rarely exceeding a foot in thickness, has been named the "insect limestone."
Many insects, and especially certain crustaceans, show us what wonderful changes of structure can be effected during development. Such changes, however, reach their acme in the so-called alternate generations of some of the lower animals.
As the chelae of Crustaceans resemble in some degree the avicularia of Polyzoa, both serving as pincers, it may be worth while to show that with the former a long series of serviceable gradations still exists.
Another weed, known by the name velp and boasting four-foot leaves, was crammed into the coral concretions and carpeted the ocean floor. It served as both nest and nourishment for myriads of crustaceans and mollusks, for crabs and cuttlefish. Here seals and otters could indulge in a sumptuous meal, mixing meat from fish with vegetables from the sea, like the English with their Irish stews.
In the paddles of the extinct gigantic sea-lizards, and in the mouths of certain suctorial crustaceans, the general pattern seems to have been thus to a certain extent obscured. There is another and equally curious branch of the present subject; namely, the comparison not of the same part in different members of a class, but of the different parts or organs in the same individual.
Sometimes they walked along the bottom, stirring to right and left of them a host of low-class life, slimy leeches, dingy crustaceans of every imaginable kind. Sometimes they traversed the middle deeps, brushing against the beetles and the boatmen and the water-snails. Sometimes they sunned themselves on the surface, snapping idly at the measurers and whirligigs.
Word Of The Day
Others Looking