FUNGI, 301 
such as muscular and nervous substance, cannot 
be replaced ; should they be destroyed, the wound 
is repaired by the formation of cellular, or some 
other of the less complex tissues. Every part of 
the fungus, however, as its structure is uniform 
throughout, can be re-formed with equal facility. 
Even the organs of reproduction, which may be 
considered its most highly organized parts, can be 
replaced or repaired if in any way injured. The 
‘tubes of the toadstool, and the gills of the mush- 
room, have been cut out and separated from the 
living plant by way of experiment, and yet in a 
brief space of time they have been so carefully 
reproduced, that no one could possibly tell they 
had ever been removed. Snails are continually 
eating holes into them, but when in active growth, 
they speedily fill them up again with new tissue. 
Puff-balls growing among grass on the borders 
of woodlands, and in the open meadows, are 
frequently very much injured by the scythe 
of the mower, cut open, and whole parts sliced 
off, but these wounds speedily heal themselves, 
and the parts that have been removed are re- 
modelled, without leaving the slightest cicatrice 
to mark the point of junction or the seat of 
injury. 
Owing likewise to this extreme simplicity of 
structure, they possess the faculty of almost inde- 
