3. The eggs may be voided by the sheep, may fall upon the herbage, and there remain till they are eaten. Such is the supposition published by Mr King of Hammersmith, in the _Quarterly Journal of Agriculture_, No. XXXI. p. 331, in which, after showing the vast number of eggs which must fall upon the grass, he says, "We must cease to wonder that so many sheep die of rot; the miracle is, that every sheep does not die of it."! I cannot, however, for my part, see a miracle in the matter, for the simple reason, that the eggs of the entozoa are not capable of retaining their vitality when absent even for a very short time from the place of their nativity, and therefore may be eaten with impunity.
II. Supposing the eggs to have reached the sheep's stomach in a condition to allow of their being hatched, they, according to popular voice, find their way into the gall bladder by one of two routes.
1. Mr King, the gentleman above spoken of, conjectures, in the same paper, that the fluke, after leaving the egg in the stomach of the sheep, _makes its way up the gall vessels_. This is, I am sorry to say, a very idle conjecture, as, from the valvular nature of the opening of the gall duct into the duodenum, an entrance from that intestine to the gall bladder is perfectly impracticable to any of the entozoa.[36]
[36] The notion that rot is occasioned by animalcules getting into the liver is not confined to this country. Leake, in his travels in the Morea, alludes to an opinion prevalent there, that the _vidhéla_ (rot) is caused by the sheep feeding in marshy places in August and September, when it is imagined that an insect from the plants finds its way into the biliary vessels.
2. The eggs are believed by a writer in the _Letters of the Bath Society of Agriculture_, for 1781, to be taken into the blood along with the chyle from the small intestines, and to be arrested in the liver by the secretory ducts. This, it must be clear to every one, is the most absurd of all the notions; for if a globule of blood, which we must suppose to be the largest body capable of being absorbed from the intestine, is only about 1/3000 of an inch in diameter, how can the egg of a fluke worm pass through the same channel, when Mr King has, by careful observation, shown it to be 1/300 an inch in its shortest measurement. Again, allowing that they are taken into the blood, would they not frequently be hatched there, and would they not also be found in other quarters besides the liver. But do we ever find them in the blood? Do we ever see them in other organs? Certainly not.