44. ANIMALS AND VEGETABLES IIL 
became perfectly tranquil. There they infenfibly 
contracted ; their fhape and colour difappeared ; 
they affumed a light chefnut fhade; and exhibited 
every fign of being changed to nymphs. In this 
ftate, they remained fourteen days; then, the 
fhell burfting, flies completely refembling the pas 
rent fly efcaped. The winged infects lived feve- 
ral days in their prifon, and died apparently for 
want of food. , 
A few words may be faid concerning the feeds 
ufed for infufions. They developed like the ani- 
malcula ; all germinated well ; and in a few days, 
the budding and branching of the leaves filled the 
capacity of my veffels. I fhould not omit ob- 
ferving, that the whole of thefe vegetations fhew- 
ed fymptoms of difeafe, whether from decaying 
before fructification or from their yellowifh co- 
Jour. Sufpecting that this difeafe was not fo 
much the effect of privation of circulating air as 
of the beneficent influence of the fun, and the 
moifture that the roots muft fupply, which 
‘could not. be obtained from the {mall quantity of 
water, I endeavoured to afcertain the real caufe. 
‘The fame quantity of feeds was put into veffels 
hermetically fealed, and, inftead of water, I fub- 
ftituted a portion of well moiftened earth. The 
plants foon fprung up ; and, being expofed in the 
‘fun beams fome hours of the day, in ‘a fhort 
time, reached the fummit of the veffel-without be- 
? coming 
