504 Prof. W. Preyer on Anabiosis. 



Now, inasmuch as the facts on which this important differ- 

 ence is based have recently been called in question, not so 

 much for spores and vegetable and animal ova as for adult 

 organisms, I will adduce a few proofs of anabiosis in animals 

 which are calculated to avert a possible relapse into the old 

 heresy of the " eternal vortex of living matter " and of the 

 so-called " vital force." They depend upon the acknowledged 

 fact that animal life is impossible without water in the state 

 of fluid drops. 



I. The Revivification of Hard-frozen Animals. 



I have often arranged and performed the following experi- 

 ment. A number of similar frogs, which have adapted them- 

 selves in winter to a temperature slightly above freezing- 

 point, are allowed to become frozen hard in snow or air at 

 several degrees below zero C. We convince ourselves that 

 the heart of one of the animals is frozen solid, and that the 

 blood is no longer in a fluid state, and we then allow the rest 

 of the frogs, which have been frozen under the same con- 

 ditions as the creature we have examined, to thaw with the 

 utmost slowness. We find that they completely recover, 

 provided that the internal temperature has in no case sunk 

 below — 2°'5 C, notwithstanding the fact that during their 

 apparent lifelessness, lasting for several hours, no metabolism, 

 no circulation or breathing, no movement of the muscles, in 

 short no vital process whatsoever, was able to take place. 

 The frozen heart too, which we removed from the frog, 

 commences to beat again by itself after thawing in the air, as 

 was likewise observed by Horvath *. A single extremity of 

 a frog after being frozen stifi" will regain its functional 

 power provided both the freezing and subsequent thawing are 

 effected very gradually, as has been proved by my own 

 experiments and those carried out by Heiuzmann under my 

 guidance f. 



Sir John Franklin, the arctic voyager (1820), in writing 

 of frogs, states that they were often found frozen hard, and 

 were revived by warmth. Dum^ril (1852) achieved the same 

 result by experiments. Richardson, the surgeon of Franklin's 

 expedition, saw fish, on being taken out of the nets at Fort 

 Enterprise in winter, become converted in a short time into 

 solid lumps of ice, so that they were easily split up with a 

 hatchet and the entrails could be removed in a lump. If, 



* ' Centralblatt f lir die medizinischen Wissenscliaften/ 1873, p, 34. 

 t Pliiger's ' Archiv f. d. gesammte Pliysiologie ' (Bonn, 1872), vi. Bd. 

 p. 235. 



