324 ANIMAL PARASITES. 



it as a distinct worm, which they found abundantly in the epidemic 

 "Morbus mucosus" observed by them, admitting it to be produced 

 by generatio cequivoca during this disease, of which they regarded 

 it as a pathognomonic indication. For a long time, indeed, it 

 was supposed that this worm only existed in the intestine of 

 typhous patients, but it has now been found that it has no par- 

 ticular relation to any disorder of the human intestine. The 

 physiological zoologist is compelled to conceive the affair in the 

 following way. The dwelling place of our worm is the lowest 

 region of the small intestine, near about the ileo-csecal valve, and 

 the large intestine with its appendages ; in short, that region of 

 the intestine in which the chyme is just becoming of a rather 

 thicker consistence. From the dingy colour of the worm, which 

 is principally caused by its feeding upon human excrement, 

 it probably escapes the eye of the observer in general, and is only 

 detected with ease when the intestines are free from the thick, 

 dark-coloured contents (the true refuse of the food). This will 

 be the case especially in disorders associated with diarrhoea of 

 long duration, or with recent, violent, very watery diarrhoea. 

 Thus probably it happened, that the worm was at first 

 found only in typhus and typhoid disorders, whilst it was 

 overlooked in the dysenteries accompanied by stagnation of 

 the faeces in the large intestine. But if we were to soften the 

 contents of the large intestine in water, and pass the faeces thus 

 softened through a fine sieve, as some people do in seeking for 

 the heads of tape-worms after attempted expulsion, we should 

 meet with the worm much more frequently. By a process of this 

 kind we should also certainly convince ourselves that authors 

 who say that these worms usually inhabit the human intestine 

 only in small numbers, or even singly, are very much in the 

 wrong, and that the numbers found by dissection are usually so 

 small only because the diarrhoea has already removed most of the 

 worms, and only the stragglers, certainly the most vigorous 

 marauders of the troop, are still to be found. Moreover, cases 

 are known in which the Trichocephali were found in considerable 

 number. Thus, even Rudolphi says, " Trichocephalus dispar in 

 hominis cceco et colo vulgatissimm, in tenuibus rarior" and further, 

 in the third observation, "in omnibus fere cadaveribus humanis 

 a me examinatis offendi Trichocephalos, semel ultra 1000 specimina 

 in femince intestinis crassis vidi. }) Bellingham also once found 

 119 specimens in the cascum alone of an individual in Dublin. 



