The excretions from the minute arterial branches ramified on the internal coat are mingled with a bland fluid from the mucous follicles, the evident use of which is to protect from injury the sensitive surface of the intestine. Occasionally, however, the mucous secretion becomes so abundant and viscid, as to adhere with unusual force, and to impede the formation and absorption of the chyle, and even the action of the usual purgatives. Worms are then common, and cannot be expelled except by remedies which tend to remove the mucus in which they live imbedded. [Illustration] To fit the mucous coat for its office of _absorption_, an immense number of minute vessels, called _absorbents_, are ramified on its internal surface, the nature and purposes of which are analogous to those mentioned in the former volume when describing the functions of the skin.[34] In both structures the absorbents are small capillary or _hair-sized_ vessels, so infinite in number that at least one goes to every little point or _papilla_. Those which open upon the inner surface of the smaller intestines, and which suck in or absorb the chyle, are called _lacteal absorbents_, or simply the _lacteals_ or milk-vessels (marked LLLL in the subjoined wood-cut), from the white colour of the chyle shining through them and giving them the appearance of vessels full of milk. In that part of the gut they are so numerous that every minute point of the villous coat may be seen by the aid of a microscope to contain one with its mouth open to receive the chyle as fast as it is formed. Even in the colon the absorbents are numerous; but, as all traces of chyle have there disappeared, they are much fewer than in the smaller intestines. In the colon they serve chiefly to remove the more watery portions of the intestinal contents, by which means the fæces are rendered more solid and less bulky, and therefore better adapted for being retained for a time without inconvenience. It sometimes happens that when food or medicine cannot be swallowed in the usual way, life is preserved by injecting it into the bowels; in which case the absorbents of the large gut become active, and carry it into the system. Strong soups, milk, opium, laxatives, and other remedies are often administered in the same way, when any reason exists against giving them by the mouth. There are absorbents in every structure of the body, because there are everywhere waste particles to be taken up and removed; but, except in the case of the lacteals, their contents are _limpid_ or colourless, and hence in other places they are called _lymphatics_: in almost every other respect, however, the two classes of vessels are analogous to each other.