152 THE WONDER OF LIFE 



70 per cent, alcohol and others for thirty hours in petroleum, 

 but they survived it all. Such is the toughness of some 

 living creatures. 



Some of the statements that have been made in regard 

 to the survival of complex animals after prolonged and 

 severe desiccation require to be revised. In some cases, at 

 least, the creatures themselves die, but eggs with specially 

 resistant envelopes (' winter-eggs ') hve on and rapidly 

 develop when there is a restoration of favourable conditions. 

 Thus D. D. Whitney (1908) found that out of forty-five 

 diSerent species of Rotifers, belonging to seventeen famihes, 

 only two, Philodina roseola and P. citrina, could success- 

 fully withstand desiccation. It seems probable that the 

 revival of adult Rotifers after desiccation is not so common 

 as has sometimes been supposed. 



An almost whimsical instance of vital resistance is 

 vouched for by G. Tornier. He found two eggs of the 

 common hzard, Lacerta agilis, through which the rhizome 

 of a sedge had grown, dissolving away the shell at the 

 entrance and exit. Each of the eggs contained a normal 

 embryo ! In the uppermost of the two eggs, which was 

 perforated centrally by the rhizome, there were actually 

 three rootlets penetrating the embryonic membranes and 

 entering the yolk-sac. In one case a dehcate rootlet had 

 passed into the embryo's mouth. Yet the embryos were 

 normal, illustrating quaintly but strikingly what we may 

 call developmental resistance. 



An eel about a foot long has been known to hve for seventy- 

 two hours without water, and a day's drought can be 

 readily withstood. This tenacity of hfe makes it easier 

 to admit the possibility of the overland journeys which 

 eels are alleged to take when occasion requires. 



