ON A NEW CESTODE LARVA PARASITIC IN MAN. 21 



is one of the Botliriocephaliche, notwithstanding the fact that the 

 head is found to be without bothria. Perhaps it is assumable 

 that a definite suctorial organ or organs might yet develop at a 

 later developmental stage of the worm than those I have had for 

 observation. Equally possible it seems, on the other hand, that 

 the head keeps up the observed simple condition even to the 

 mature stage, — that we have here to do with a Bothriocephalid 

 which has lost all trace of bothria. Perhaps these are wanting 

 in the so-called Ligula mansoni also ; at any rate they have never 

 yet been seen with certainty in that larval Cestode. Accordingly 

 it may possibly turn out that " Ligula mansoni " and Plerocer- 

 Goides prolifer represent very nearly related forms, perhaps 

 generically identical. A more exact systematic determination of 

 the larval forms can not be made with certainty until they have 

 been traced up to the sexually mature stage. 



I consider it futile to enter here into speculations concerning 

 the past and future life-history of the larval Cestode described 

 in this paper. Great interest is of course attached to feeding 

 certain animals {e. g., cats, dogs, or pigs) with the larvse for the 

 purpose of raising the mature worm, and also to determining if 

 they can be operatively transplanted into the connective tissue of 

 animals and there made to proliferate. Experiments in these 

 directions I have caused to be made by Professor Kondö's assis- 

 tants, but unfortunately they have borne no fruit. As the patient's 

 return to the hospital is held in prospect, I am in hope of 

 obtaining a new supply of the material with which to renew the 

 experiments. 



