So much then of the gall-bladder, and of the reasons why some animals have one, while others have not. We have still to speak of the mesentery and the omentum; for these are associated with the parts already described and contained in the same cavity. The omentum, then, is a membrane containing fat; the fat being suet or lard, according as the fat of the animal generally is of the former or latter description. What kinds of animals are so distinguished has been already set forth in an earlier part of this treatise. This membrane, alike in animals that have a single and in those that have a multiple stomach, grows from the middle of that organ, along a line which is marked on it like a seam. Thus attached, it covers the rest of the stomach and the greater part of the bowels, and this alike in all sanguineous animals, whether they live on land or in water. Now the development of this part into such a form as has been described is the result of necessity. For, whenever solid and fluid are mixed together and heated, the surface invariably becomes membranous and skin-like. But the region in which the omentum lies is full of nutriment of such a mixed character. Moreover, in consequence of the close texture of the membrane, that portion of the sanguineous nutriment will alone filter into it which is of a greasy character; for this portion is composed of the finest particles; and when it has so filtered in, it will be concocted by the heat of the part, and will be converted into suet or lard, and will not acquire a flesh-like or sanguineous constitution. The development, then, of the omentum is simply the result of necessity. But when once formed, it is used by nature for an end, namely, to facilitate and to hasten the concoction of food. For all that is hot aids concoction; and fat is hot, and the omentum is fat. This too explains why it hangs from the middle of the stomach; for the upper part of the stomach has no need of it, being assisted in concoction by the adjacent liver. Thus much as concerns the omentum.
同类推荐
热门推荐
十两相思话别生死怨念
云胡在偶然的一天,强行唤醒了他们家族身体里的一股神秘力量——发现了亡者与活人之间的连接。更想不到的是,她遇见了300前,用血玉修成精的叔祖,一个长相俊美的翩翩公子。他以为云胡就是他寻了300年的昭蓉,便一直陪着她,看遍人性的冷漠和温暖,帮她改变了桎梏的生活。直到他看到想霸占云胡身体的昭蓉时,才发现是自己造就了云胡遭遇到的一切。好父母都是故事大王
“破坏大王”的心里话——引导孩子爱惜物品并不难。洗面奶在沙发上晒太阳,润唇膏被涂上了墙,新买的玩具车被“肢解”得遍地都是,拿着马桶刷学着大人的样子拖地……每个有孩子的家庭都可能会上演这一幕幕令人哭笑不得的场景,有的家长看到物品被孩子糟蹋了,轻则大声斥责,重则动用武力,尽管你使出浑身解数,依然很难改变孩子破坏东西的坏毛病。难道孩子天生是破坏大王不成?没错,“破坏”是孩子成长发育过程中常会出现的现象,但破坏的原因却是多种多样的,有可能是因为孩子的好奇心和探索欲望使然,也有可能是动作发展上的需要,亦或者是发泄不满情绪。要想让孩子养成珍惜物品的习惯,就应该先找出孩子破坏背后的“真相”,然后再因势利导。