登陆注册
5260800000016

第16章 3(2)

In what sense, then, the blood is hot and in what sense fluid, and how far it partakes of the opposite properties, has now been fairly explained. Now since everything that grows must take nourishment, and nutriment in all cases consists of fluid and solid substances, and since it is by the force of heat that these are concocted and changed, it follows that all living things, animals and plants alike, must on this account, if on no other, have a natural source of heat. This natural heat, moreover, must belong to many parts, seeing that the organs by which the various elaborations of the food are effected are many in number. For first of all there is the mouth and the parts inside the mouth, on which the first share in the duty clearly devolves, in such animals at least as live on food which requires disintegration. The mouth, however, does not actually concoct the food, but merely facilitates concoction; for the subdivision of the food into small bits facilitates the action of heat upon it. After the mouth come the upper and the lower abdominal cavities, and here it is that concoction is effected by the aid of natural heat. Again, just as there is a channel for the admission of the unconcocted food into the stomach, namely the mouth, and in some animals the so-called oesophagus, which is continuous with the mouth and reaches to the stomach, so must there also be other and more numerous channels by which the concocted food or nutriment shall pass out of the stomach and intestines into the body at large, and to which these cavities shall serve as a kind of manger. For plants get their food from the earth by means of their roots; and this food is already elaborated when taken in, which is the reason why plants produce no excrement, the earth and its heat serving them in the stead of a stomach. But animals, with scarcely an exception, and conspicuously all such as are capable of locomotion, are provided with a stomachal sac, which is as it were an internal substitute for the earth. They must therefore have some instrument which shall correspond to the roots of plants, with which they may absorb their food from this sac, so that the proper end of the successive stages of concoction may at last be attained. The mouth then, its duty done, passes over the food to the stomach, and there must necessarily be something to receive it in turn from this. This something is furnished by the bloodvessels, which run throughout the whole extent of the mesentery from its lowest part right up to the stomach. A description of these will be found in the treatises on Anatomy and Natural History. Now as there is a receptacle for the entire matter taken as food, and also a receptacle for its excremental residue, and again a third receptacle, namely the vessels, which serve as such for the blood, it is plain that this blood must be the final nutritive material in such animals as have it; while in bloodless animals the same is the case with the fluid which represents the blood. This explains why the blood diminishes in quantity when no food is taken, and increases when much is consumed, and also why it becomes healthy and unhealthy according as the food is of the one or the other character. These facts, then, and others of a like kind, make it plain that the purpose of the blood in sanguineous animals is to subserve the nutrition of the body. They also explain why no more sensation is produced by touching the blood than by touching one of the excretions or the food, whereas when the flesh is touched sensation is produced. For the blood is not continuous nor united by growth with the flesh, but simply lies loose in its receptacle, that is in the heart and vessels. The manner in which the parts grow at the expense of the blood, and indeed the whole question of nutrition, will find a more suitable place for exposition in the treatise on Generation, and in other writings. For our present purpose all that need be said is that the blood exists for the sake of nutrition, that is the nutrition of the parts; and with this much let us therefore content ourselves.

同类推荐
  • 金匮玉函要略述义

    金匮玉函要略述义

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 棋诀

    棋诀

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 碣石调幽兰

    碣石调幽兰

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • What Diantha Did

    What Diantha Did

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • The Voyages of Doctor Dolittle

    The Voyages of Doctor Dolittle

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
热门推荐
  • 去东京寻找妹妹

    去东京寻找妹妹

    女孩喘息了一下,嘴唇在翕动:“……快找、找我哥哥……”妹妹成品在东京失踪了!那天早晨,我正在亲贤街附近的一家小酒吧门口和我的搭档麦克蹲守一笔毒品交易,那会儿目标还没有出现,麦克说在车里堵得慌,要出去透透气。我打开了车上的调频收音机,听到东京地铁出口发生大爆炸的消息,我忽然记起成品就在离地铁出口不远处的浅草歌舞伎模特经纪公司上班,心里顿时各种念头丛生,便急忙拿出手机拨打她的电话,却被告知关机了。我又打到了她租住屋里,电话通了,却一直没有人接听。
  • 重生之万界称尊

    重生之万界称尊

    重生混沌历经百战终于成就至高无上。可是一切真的那么简单吗?洪荒真的是尽头吗,那洪荒的尽头又是什么呢,那无尽的轮回深处到底演绎着一个什么故事。
  • 柯南VS网王之两个世界的秘密

    柯南VS网王之两个世界的秘密

    开头未定,此书是两本合在一起的小说。前面的话写的不是很好,不要看到前面就弃书啊,现在要不知道怎么改,就先没动,一定要看到后面在决定弃不弃书!!!网王里有两个女主,会比较玄幻柯南的话女主比较普通,不会是那种什么都行的女主,剧情可能有点狗血女主的话肯定会比较心里年龄成熟一点,不是那种什么都不会什么都不知道的女主大修中……
  • 岁月如歌

    岁月如歌

    本书对阆中市人大常委会的工作进行了回顾,内容涉及“主任视窗”、“铿锵足音”、“府院连线”、“大事回眸”等。
  • 腹黑竹马:拐个青梅当老婆

    腹黑竹马:拐个青梅当老婆

    7岁相遇;12岁相认;15相知;17互相暗恋却又小心翼翼的守护自己的感情。他是五大家族之首夜家长子,高冷帅气优秀;她是五大家族尹家小公主,活泼可爱,机智聪明,被五大家族捧在手心里。夜寒墨知道自己这辈子注定栽在尹亦曦手上,看着她笑,他也开心;看着她皱眉,他也不开心。他爱她入骨,势力滔天的他,却又胆小的不敢表达自己的心意;殊不知被他爱入骨的她,早已把一颗心给了他,只等他一句“我爱你。”有时候,我们爱的太骄傲,骄傲到认为对方会明白自己的心意;有时候,我们有太自卑,自卑到没有勇气表达自己的爱。这是一个腹黑少爷和呆萌少女的爱情故事,男女主身心健康。不喜勿喷,禁止转载。
  • 魔术不难(走进魔术世界)

    魔术不难(走进魔术世界)

    《走进魔术世界:魔术不难》就是抱着这个让你成为小小表演者的目的来编排的,力求内容广泛,语言浅显易懂,让你一学就会。相信聪明的你在仔细地阅读完《走进魔术世界:魔术不难》后,定会成为人人称羡的表演者。
  • 小食物·大功效全集

    小食物·大功效全集

    如果你想了解更多的食物常识,掌握养生保健食疗、美容食疗以及疾病食疗方法,成为自己生活中的营养师,那么请翻开此书,相信作为一本健康手册,它将带给你最实用、最新颖、最完整的饮食帮助,成为你健康生活的良师益友。
  • Man and Wife

    Man and Wife

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 神秘的未解之谜(上)

    神秘的未解之谜(上)

    亲爱的小伙伴:你听说过用鼻子行走的怪兽吗?你知道月亮的背面有外星人基地吗?你猜尼斯湖水怪到底是不是蛇颈龙?抹香鲸和大王乌贼到底谁更厉害?复活节岛上的石像是不是外星人做的?水熊虫为什么冻不死也煮不熟?吸血鬼真的存在吗?哈哈!我们生活的地球上有很多科学家都不知道答案的问题,你想不想听听这些稀奇古怪的事情?宝贝听听独家制作的“儿童探索百科故事”带你畅游神秘的世界!著名故事大师“夜爸爸”和未来小机器人共同播讲!
  • 天才魔妃很妖孽

    天才魔妃很妖孽

    21世纪腹黑又机灵的女佣兵,一朝穿越到圣洛大陆冰家废物五小姐身上,异世中看病猫如何化身为猛虎,狂傲天下。“娘子。”一个美男看着冰璃儿笑眯眯的亲昵叫道。冰璃儿睁大错谔的双眸,一阵风中凌乱,少顷,破口大骂道,“你妹的娘子,你妹夫的娘子,你也不看看你才多大,就想着娘子,告诉你,我不会和你谈恋爱的。”“我没有妹,也没有妹夫!”美男睁着一双水盈盈的桃花眼卖萌道。“………”冰璃儿无语望天。【女佣兵系列四】这是一个强姐姐和强哥哥的故事,各种美男,各种萌,各种爆笑,轻松宠文。