542 
Experimentation in Biology. [September, 
in the case of the Arachnida, while in slugs and snails the 
flow of mucous carries away the irritating matter. Several 
experiments were made on the earthworm, and eleven on a 
species of anemone ( Actinia mesembryanthemum) : of these 
one is of unusual interest ; a piece of the animal was 
excised, and the edges of the wound inverted ; some convo- 
luted perivisceral tubes were upon the outer surface : after 
two days the wound was still unhealed, but upon the appli- 
cation of blistering fluid the wound was closed by the pro- 
trusion of a fresh supply of convoluted tubes ; these, after 
a month’s interval, underwent complete granular degenera- 
tion. How pregnant was John Hunter’s phrase “ stimulus 
of necessity ” ! Must we believe the pseudopodial moneron 
to be, with manual Man, the prince of inventors ? 
(To be continued.) 
