Appendix. 



Professor Cantoni,* of the University of Pavia, by means of a 

 Papin's digester, carried the temperature of his flasks to uo- 

 117 Centigrade, and yet vibrios in large number, were produced 

 in two days. And Dr. Bastian has repeatedly noted a tempera- 

 ture ranging from 148 to 150 C. (equal to 312 F.) to which 

 his infusions have been submitted for a brief period, and yet liv- 

 ing matter has soon developed. On the other hand, some of the 

 living infusoria will flourish in temperatures below the freezing 

 point. They may even be dried and kept for years and then by 

 the application of moisture they will revive and resume active 

 motion. The truth seems to be that the germs, 'at least, are of 

 well nigh inextinguishable** vitality, but it is difficult, if not im- 

 possible, to secure consent as to the precise limits of temperature, 

 wet and dry, and other conditions under which such vitality may 

 be retained. Until these points can be determined it seems al- 

 most hopeless to expect a solution which will command assent 

 from both parties to the controversy. 



* Gaz. Med. Ital. Lombard., Ser. VI., Vol. 1, 1868. It is a significant fact in 

 this connection that Cantoiii's,Wyman's,Huizinger's,and others' experiments 

 have been interpreted by the adherents of opposite sides of the question as 

 substantiating their own view of the matter. 



** " The tenacity of life [of the Rotiferse] is one of the most extraordinary 

 phenomena. Their resistance to cold is something marvellous, and we don't 

 even know where it stops ; the lowest temperature that we can obtain in our 

 laboratories does not seem to have any effect upon them * * * I have 

 sometimes removed them quickly from the freezing apparatus and thrown 

 them into a stove heated to 176 Fahr. * * * In this two-fold test and for- 

 midable transition from cold to heat, these microzoa passed rapidly through 

 a change of 216 Fahr. without being in the least inconvenienced by it." 

 Pouchet. Tlie Universe, p. 56. 2d Ed., 1871. 



RUDOLPHI long ago learned that the entozoa in frozen fish when thawed 

 out resumed their customary 'activity. FRANKLAND has recently described 

 ice-fleas, which flourish in the glaciers of the Alps, at a temperature con- 

 stantly below freezing point. 



MR. BAUER kept the vibrio tritictB, parasite of wheat dried for seven 

 years, and on moistening them with water they resumed their active mo- 

 tions. . 



M. BALBIANI in 1857 "observed a drop of water on a plate of glass in 

 which were living colpods. When the water was evaporated each became 

 encysted and- dormant in its envelope. The plate was moistened again in 

 1864, when every colpod was observed to come out from its shell and prompt- 

 ly resume its vital functions, which had been interrupted by seven years of 

 sleep." Revue des deux Mondcs, Vol. LIV., 1864, p. 439. 



