Royal Microscopical Society. 209 



the pump (of course without acid) for two days without their dying 

 or showing much signs of distress. 



As regards the " unlimited duration " of time they may be kept 

 alive in their dry cases, authorities differ : my experience, founded 

 on unsuccessful attempts to revive three samples of dust after five 

 years' drought, two after three years, and one after one year, leads 

 me to rate their longevity within moderate limits ; but there is 

 evidence of their revival after four years' torpor. 



In conclusion, I will quote the great Ehrenberg, who without 

 these experiments, in spite of apparently overwhelming evidence to 

 the contrary — evidence considered up to the present time as per- 

 fectly conclusive — and led only by analogy and reason, arrived at 

 the same results that I have now the honour to place, with proofs, 

 before you : — " Whenever these creatures are completely desiccated, 

 life can never again be restored. In this respect the Kotifera 

 exactly correspond with larger animals ; like them, they may con- 

 tinue in a lethargic and motionless condition ; but there will be 

 going on within them a wasting away of the body, equivalent to 

 so much nourishment from without as would be needed for the 

 sustentation of life." 



