CESTODA 67 



50 C. (122 Fahr.). In May, 1877, Dr Perroncito furnished 

 me with, an account of his researches. With the exception of 

 a few verbal alterations, for which I am responsible, Perroncito 

 wrote as follows : 



" In order to resolve the highly important question of the 

 tenacity of life of the Helminths and corresponding larval 

 forms, I made since 1871 a very long series of experiments on 

 the Cysticercus cellulosce, which were published almost at the 

 same time with others of the same kind, made by Dr Lewis in 

 Calcutta. Towards the end of 1874 Mr Pellizzari, of Florence, 

 disputed the results of the investigations which I had made 

 known two years before, i.e. in 1872, and agreed with Dr Lewis, 

 who had stated already that the Cysticercus exposed to a tem- 

 perature of 55 C. can be held for dead after five minutes, and 

 also with Dr Cobbold, who thought the temperature of 60 C. 

 quite enough to kill it. But the characters he (Mr Pellizzari) 

 relied upon, needing the exactness and precision required to 

 enlighten and persuade in the most important scientific questions, 

 gave rise to a mistrust in the most scrupulous amongst the men 

 devoted to biological pursuits and to several hygienic measures 

 on the part of the sanitary inspectors with regard to in- 

 fected pork. Therefore, my conclusions, argued from the 

 experiments made in 1871-72, were still those followed by the 

 most important Italian cities, and approved in principle by the 

 superior Board of Health in 1873. I expressed doubt theo 

 about the Cysticercus dying at a temperature lower than 100 C., 

 and some person misconstrued these doubts, saying that I 

 had contradicted myself in my work. However, as I could not 

 assert they died at 80 100 C., I only noticed the alteration 

 of color and cohesion which happened in the Cysticercus 

 exposed to various degrees of temperature, to the end that I 

 might contribute usefully to the solution of the difficult ques- 

 tion, and concluded that ' if we could not be sure of the 

 Cysticercus dying at 80 100 C., it was certain at all events 

 that they perished at 125 or 130 C.' Not wishing to pre- 

 judice the question, I never said that they did not die at 80 

 100C., but simply stated that at this temperature we could 

 not be certain of their death. 



"Now, after a large number of experiments, I have been 

 able to ascertain with exactness the lowest degree of temperature 

 required to kill infallibly the Cysticercus and other parasites of 

 animals. The means I made use of for this kind of investiga- 



