IN THE BODIES OF ANIMALS. 385 



removed from the body of a fish. Where, I would ask, would 

 the worms find a suitable kind of nourishment, or a place of 

 abode in any respect resembling the situation they had left? If 

 worms pass in and out of the animal body in the mode which 

 Bremser would have us to believe, they certainly should be far 

 more numerous than they are, we should meet with them more 

 frequently, and they would promiscuously infest every animal 

 to whom they should be accessible. 



Those who have failed in supporting this position, still tena- 

 cious of their opinion, bring it forward in a new dress, and 

 maintain that worms undergo a positive metamorphosis in the 

 body of the animal, or, in some way or other, accommodate 

 themselves to the change. But is this true ? For aquatic or 

 terrestrial worms carried into the body by accident, soon die, 

 and that from two causes ; for they either suffer digestion, or 

 sink under the increased temperature. I have often found 

 extraneous worms in many animals, but invariably dead, and 

 more or less digested ; they may be found chiefly in the 

 stomachs of mice, moles, hedge-hogs, birds, and fishes. These 

 facts alone are sufficient to prove the difference between ex- 

 trinsic and parasitic worms, because those of the latter class, 

 which pass their lives in the oesophagus, stomach, and intes- 

 tines, resist the solvent power of the gastric and intestinal 

 fluids, and the triturating force exercised by the stomach : 

 indeed, I have often seen in the stomach of the common pigeon, 

 the lining membrane of which is nearly as hard as that of the 

 fowl, abundance of Tcenia and Amphistomata attached to it ; 

 and even when the bird had been dead ten hours, I have found 

 them adherent to the inner coat of the stomach. What extra- 

 neous worms, I would ask, could resist the power of such a 

 stomach ? I am well persuaded that none could ; but even 

 supposing this possible, the natural temperature of the first 

 orders of animals would prove rapidly fatal to them. Frequent 

 mention is made by authors of the Gordius aquaticus, or 

 hair-tail worm, having found its way into the bodies of men 

 and horses ; and Pallas himself relates an instance. The subject 

 of it was a man, who some days after washing in a river, per- 

 ceived on the dorsum of his feet an inflamed spot, of about an 

 inch in diameter. The centre was rendered somewhat promi- 

 nent by the presence of a projecting Gordius, of a darkish 

 colour, not unlike a horse-hair ; on attempting to remove it 



NO. IV. VOL. III. 3 D 



