EX VI RIB US VIVIMUS. 



of life of all separated and independent organized 

 masses; the branch is part of the individual tree 

 while it is attached thereto ; but if it be removed 

 when young and grafted or bedded, it is a new in- 

 dividuality and has its own longevity. So with the 

 bedded polyps or worm-segments : whilst attached, 

 they have but one individuality ; when thrown off or 

 disunited by the death of their common parent or 

 axis, they are distinct individualities. Though not 

 fully satisfactory, such seems to be the fittest use of 

 the word ' individual ' in relation to our subject. 



Certain difficulties are also involved in the term 

 ' life.' For, whilst in this essay it is beside the subject 

 to enter into an explanation or definition of that 

 phenomenon, we are certainly called upon to consider 

 whether, in defining longevity as the duration of life 

 of an individual, we regard the suspended animation 

 of such organisms as Rotifera, Tardigrada, and some 

 Nematodes, as also the retarded development of 

 seeds, such as those of Egyptian wheat obtained 

 from the most ancient monuments, as coming into 

 consideration as instances of duration of life. The. 

 best solution which can be given of this difficulty 

 appears to be in regarding these cases as strictly 

 exceptional, and as being rather examples of suspen- 

 sion of life than of its duration. Though the condi- 

 tions under which this suspension occurs may furnish 

 some evidence as to the conditions favourable to the 

 retention of vitality by an organism, they must be 



