FALSE PABASlMsV r lOl 



at the anterior extremity, and a larger abdominal apertufe before 

 the tail, found in an ovarian fat-sac, is in my opinion so doubt- 

 ful, that I think I am justified in leaving it out, although 

 Bremser figures it amongst the Helmintha. Treutler thinks 

 that this animal resembled the Linguatula. ; and although 

 other views have been recently put forward, I cannot help con- 

 sidering the thing as impossible. Errors are very possible, 

 especially with such low powers as Treutler appears to have 

 employed. The animal in question cannot well have been a 

 Pofystomum, which has hitherto only been found in the air-pas- 

 sages of fishes or the urinary bladder of the frog. It might, how- 

 ever, be possible that the animal, if no Linguatula, was a dead 

 hexabothrious scolex of a Tsenia, which had either lost its hooks, 

 or had not yet come to their formation. Since we have learnt 

 how to produce Cysticerci artificially, it will be admitted that 

 those forms of cystic worms have a very great similarity to 

 Linguatulce in their external form. 11. Brera's Cercosoma in the 

 urine were nothing more than thelarvse ofEristalis tenax, so com- 

 mon in privies, and which had got accidentally into the chamber- 

 pot. 12. The parasites given to Yon Baer as having been passed 

 with the faeces, which Von Baer recognised as Iarva3 and beetles of 

 Ptinus fur. It afterwards appeared that the night-chair of the 

 patient in question had a torn cushion on its seat. In putting 

 on the cover, these insects fell into the pan. 13. The hexapod 

 larva of Clerus formicarius was given to Von Siebold as a 

 urinary parasite. Both as a larva and beetle this animal preys 

 upon the bark- and wood-beetles, such as the Anobia, which live 

 in wooden furniture and in the rafters and deals of rooms and 

 houses. It might, therefore, easily have got accidentally into 

 a chamber-pot. The larvse of the churchyard-beetle (Blaps 

 mortisaga) and the woodlice (Oniscus murarius) have also made 

 their appearance as parasites. 1 



1 The most ancient example of pseudo-parasites occurs in Plutarch's ' Symposiacon,' 

 viii, quaest. 9, cap. 3. After the quotation about the Filaria medinensis he tells of a 

 person suffering from dysuria, from whom a jointed barley-stalk passed out of the 

 urethra. Probably the individual had first (horrilile dictu) put it into the urethra him- 

 self. Plutarch then narrates: " And of our guest-friend Ephebos at Athens we know, 

 that simultaneously with much seinen he evac-uated a very hairy animal which ran along 

 rapidly with many feet." Whether in this case a woodlouse, or if " caav " should sig- 

 nify " rough, hard," an earwig had penetrated into the urethra of Ephebos, and excited 

 a pollution, we cannot say. Perhaps even the worm only came subsequently to the 



