EXTRACTS AND ABSTRACTS FROM FOREIGN JOURNALS. 253 



ova rapidly developed by the influence of the water, and giving birth to 

 animalculse whose growth would be equally rapid. 



Finally, there are other physiologists who consider that the Rotifera, 

 &c., of dry sand do not undergo a complete desiccation, but such a 

 degree of it only, as to plunge them into a sort of torpor, and conceive 

 that these animalculse, although to all appearance dead, yet preserve a 

 latent life, but still a real life sufficient to establish a bond of connec- 

 tion between the active life which precedes the evaporation of the fluids, 

 and that equally active, when they are restored by the addition of 

 humidity to the full exercise of their functions. 



The observations of M. Doyere overturn all these hypotheses, and 

 confirm in the clearest way, the results obtained by Spallanzani : 



Thus, in answer to the arguments employed by Ehrenberg, it is suffi- 

 cient to observe, that living Tardigrada are never found in the dry dust 

 of gutters, but that, by the aid of the microscope, corpuscles can be 

 seen which entirely resemble the dead bodies of these animalculse, 

 deformed by desiccation, and that in matters where no living being was 

 previously discernible, living Tardigrada frequently appear on the addi- 

 tion of a little distilled water. M. Doyere is even assured that it is not 

 impossible to revivify these animalculse, if taken one by one and dried 

 separately on pieces of glass, without being surrounded with sand or 

 other material, organic or inorganic, capable of preserving them from 

 the ordinary effects of evaporation. 



In his experiments he has been able to count them, and to trace in 

 each separate individual ail the phases of desiccation ; to observe them 

 gradually assume the appearance of dead bodies, and to determine after- 

 wards that these same bodies, dry and brittle, are susceptible of reas- 

 suming their primitive form, and of returning to life under the influence 

 merely of a few drops of water. 



This experiment appears to be decisive ; but it may still be asked, 

 whether the drying which the animalculse have undergone has been 

 complete, and if the privation of all the water contained in their tissue, 

 would not render them incapable of resurrection, after having in this 

 way passed years in a state of apparent death ? 



In order to determine satisfactorily this highly interesting physiolo- 

 gical question, M. D. had recourse to the most powerful means of desic- 

 cation employed by chemists in the analysis of organic substances. 



He suspended for five days, in the vacuum of the air-pump, over a 

 vessel containing pure sulphuric acid, some Tardigrada surrounded with 

 sand, or uncovered and dried upon slips of glass ; and he left others 

 during thirty days, in the Torricellian vacuum, dried by chloride of cal- 

 cium ; and in all these instances he obtained some resurrections. These 

 results are of great importance towards the solution of the question 

 which M. Doyere had proposed to himself ; but he still conceived that 

 they might be considered as offering only a strong probability in favour 

 of the complete desiccation of the animalcube, in which the faculty of 

 becoming revivified was retained ; he continued his experiments, and by 

 studying the influence of elevated temperatures upon these singular 

 beings, he arrived at the discovery of the most decisive and surprising 

 facts. 



