178 ' DB. T. S. COBBOLD ON CESTOID ENTOZOA. 



destroys the vitality of the ova and their contained six-hooked 

 embryos. 



Exp. 3. On the 30th of May, 1865, thirty proglottides, and on 

 the 17th of the following June, fifty more (the parasite, in each 

 case, being subsequently ascertained to belong to the species 

 called Ttsnia mediocanellatd) were given to a young pig. Again, 

 on the 22nd of June, same year, I had the satisfaction of pro- 

 curing (through the kindness of Dr. M'Kendrick, Physician to 

 the Leman-street Dispensary, London) sixty perfect, fresh, and 

 fully mature segments of an undoubted example of Tania solitim. 

 These were administered to the pig by Mr. Simonds without any 

 delay. In this case, therefore, I had every reason to anticipate a 

 successful result. The animal was not killed, however, until the 

 4th of April, 1866 (the same day as that on which the heifer was 

 slaughtered), when no traces of any measles were detected. If, 

 as I think quite possible, measles had developed themselves and 

 subsequently undergone calcareous degeneration, the pale colour 

 of the pig's flesh may have prevented my detecting them. But 

 for the dark colour of the muscular tissue, in the case of the 

 heifer, I certainly never should have detected the degenerated beef- 

 tapeworm-larvse. At all events this is the only explanation I can 

 offer. The experiment, as regards its results, had certainly been 

 allowed to stand over too long. 



In conclusion, it may be remarked that, notwithstanding this 

 want of success in respect of the two last-named species, we have 

 every reason to be satisfied with the results obtained in the cases 

 of Tcsnia mediocanellata, T. serrata, T. marginata, and T. ccenurus. 



In addition to the above-recorded experiments with T. medioea- 

 nellata, it may be mentioned that we gave a sheep a single " feed- 

 ing," consisting of forty proglottides of this tapeworm ; but from 

 the negative experiences previously obtained by Leuckart in this 

 relation, I felt sure that we could only get a similar result. The 

 recent discovery of measles (furnished with hooks) in mutton by 

 Mr. Charles Heisch, E.C.S., and also, independently, by myself, 

 has inclined me to look for a third and distinct species of tape- 

 worm as the progenitor of the armed mutton-measle. I have al- 

 ready remarked, in the appendix to my recent practical work on 

 " Tapeworms " (p. 83), that the species in its adult state may turn 

 out to belong to one of the higher carnivora, and not to man. 

 Lastly, I may add that Mr. Simonds and myself have conducted a 

 number of experiments with Trichina, the results of which I shall 

 lay before the Society shortly. 



