IV. AND REVIVED. 179 
till the end of Oftober, a ditch for watering land 
covered fifty times with the beautiful verdure of 
the tremella, and feen it as often difappear; when 
there was no water. Colourlefs hairs or wool 
only were vifible at the fides and the bottom, 
which, the microfcope fhewed me, confifted of 
the tremella dry and dead: 
What can be the reafon why thefe animals 
and plants are thus privileged, in comparifon to 
many others which, perifhing once, perifh for 
ever ?—Shall we perhaps afcribe it to the fimplt- 
city of their ftructure ? But this opinion or con- 
jecture does not feem well founded: There are 
many animals that never revive; whofe ftruCture 
is as fimple, or even more fo, than that of the re- 
furgent animals. Are not many infufion animal- 
cula, which are compofed of a fimple aggregate 
of veficles,; undoubtedly lefs complex than wheel 
animals, which are provided with veffels, wheels, 
inteftines; and ovaries? Yet they do not re- 
cover life when once it is loft. Simplicity of 
ftructure would even feem an obftacle to their re- 
furrection ; for the fimple membrane of feverat 
fpecies burfts on evaporation of the water: the 
animal is difperfed, and reduced to an unconneca 
ted and difordered heap of frayments. 
The arm-polypus is no lefs fimple than the 
animalcula of infufions, being compofed but of a 
granulated gelatinous fkin: If fimplicity of ftruc- 
M 2 ture 
