INTRODUCTION. 11 



All animated matter hosa tendency and a desire for self-preservation 

 Hut all living beingB are liable to perish from disease or from accident 



l' -tilcnce i- Itorne on the winds and mi the waters. 



.Iiid-rinu' from tin' animal- them-rlvcs, they offer no suilicient data 

 enabling us to conjee-tun- tin- duration of lift-. 



Though denied to entire genera, longevity may be granted to indi- 

 viduals. A m on;: the lower orders, life in assuredly longer than tisiiallv 

 allotted to tin-in by mankind. 



- . ml noti-d example might IK- given. Of two ArtinijD, one sur- 

 vived twi-nt \ -two \e.ii> in my possession, during which time it produced 

 ri 300 young. Tlie aspect of th<- other underwent on important 

 change, for the fir-t time, duriim the lifteenth and Mxtet-nth years of it 

 life in captivity. Neither of them could ]>e loss than thirty years old at 

 the jvriod of these observations. Likewise the inluihitant of a minute 

 .-hell had survived nearly nine years, when it was destroyed by another 

 animal accidentally hmujrht to it- \ieinity. 



\\ re not decay and death essential elements in the constitution of 

 the universe, it would plainly be rendered inadequate for the reception of 

 its multiplying inhaditanta. 



Thus there is a continual waste and a constant replenishment. 



A suspension of the active and passive animal faculties, and of con- 

 scious existence, ensues in sleep, and i-spi-eially from that kind of it deno- 

 minated torpidity. 



The sleep of plants bears some analogy to the insensibility betrayed 

 liy animal-. 



Another kind of suspended animation, protracted even for years, 

 was discovered a consideraMe time ago, by a distinguished Italian natu- 

 ral i-t : and on eminent French physiologist has recently revived the sub- 

 .jvt by a learned treat i-e on the species of an entire genus endowed with 

 this remarkable property. Specimens removed from their native abode, 

 and allowed to dry. Urome motionless and insensible, and so they may 

 remain without extinction of life, until revived by humectation, after 

 the lapse of years. 



Humidity seems indispensable for demon-t nit ions of the vital prin- 



