ANIMAL PARASITES. 143 



mid defects in the speech ; and eleven times shifting pains 

 in various parts of the body. All these symptoms, however, are 

 deceptive, if we should ascribe them to the presence of the 

 tape-worm. Very often, when they are present, they do not 

 disappear even when the worm has been expelled, a proof that 

 the latter is not their first cause. Meyer Ahrens, and before him 

 Bruce and Ruppell, mention that, according to the belief of the 

 Abyssinians, the tape-worms only thrive in a healthy intestine, 

 so that the} r regard it as a sign of illness when they harbour no 

 worm. It is clear that this faith has some foundation ; but it is 

 equally clear that exceptions occur. All that has been said, 

 therefore, furnishes no absolute data for the diagnosis, not even 

 though the mode of life of the patient, his residence in certain 

 districts particularly notorious for Cestoidea, his trade or certain of 

 his habits might have furnished favorable moments for the 

 acquisition of tape-worms. Under all circumstances there is 

 but one certain diagnostic phenomenon, that is to say, the 

 emission of segments, or series of segments, of cestode worms. 

 This issuing of the segments may take place in several ways, by 

 the anus or the mouth, or through abnormal openings in the 

 walls of the intestine and abdomen. The way per anum is taken 

 by the worm either simultaneously with the fasces, especially 

 when these are diarrhceal, or without this accompaniment. This 

 is the commonest way. The second, per os, is an extremely rare 

 way, but it may occur in violent vomiting, especially with intus- 

 susception. It may, perhaps, be explained by the circumstance, 

 that the segments cast off prefer to proceed towards the side to 

 •which the posterior part of their body is directed. This may 

 perhaps be concluded from those dissections of animals in which 

 we find the head nearest to the anus and the hinder extremity of 

 the body nearest to the mouth, and perhaps also freely cast off 

 segments on the way towards the stomach. I saw the latter, for 

 instance, in a Tom-cat, from the mouth of which proglottides 

 crept a few hours after death, and in which the head of the worm 

 was situated towards the anus and the hinder extremity towards 

 the stomach, whilst free segments were moving about between the 

 stomach and the hinder end of the worm. The last course, 

 through abnormal openings in the walls of the intestine and the 

 abdomen, lias often been doubted by authors, and was described 

 by the ancients as the passage of the tape-worm through tho 

 navel, &c. When the bearer of a tape-worm has a wound in the 



