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
观察记录:母爱与死亡
这篇科幻小说以现实的唐山大地震和虚拟的100年后旧金山大地震为背景,描述了不同时代下的人类家庭结构和道德底线。唐山大地震中,一位母亲为了救自己的儿子,在奶水耗尽的情况下用血哺之,最后儿子活了母亲死了;旧金山大地震中,一位名义上的母亲(其女儿用其口腔上皮细胞克隆、并通过人工子宫孕育、由机器人保姆照料)在开始的情况下为其女儿想尽办法,最后无法抵挡饥饿,在理性思考后,吃掉了死去女儿的手臂最终获救。她被救出后,“21世纪的人类社会平静地接纳了她,没有舆论的指责。”花季那年,我们都沉沦过
如果不是夕阳西下的那个侧脸,不是那个懵懂的岁月里遇见那场盛开的烟花,也许所有的一切都不会这么复杂,可是,命运在冥冥之中便注定,有一种爱,叫做轮回。它不是生离死别,而是撕心裂肺。