18 
are these plates arranged ? It is impossible by any 
amount of ingenuity to arrange a greater number of 
such plates symmetrically in the same area. In the 
first place they radiate from the centre to the circum¬ 
ference ; then others are interposed in exact nume¬ 
rical px-oportions, not touching the cii'cumference ; and 
from this others are finally so directed inwards as to 
fill every vacant space. We see here a repetition of 
figures as regular as if they were described by the 
rule and compasses, and the result is exquisite beauty. 
Take the half-transparent Campanulate Agaric ; ob¬ 
serve the mode in which its rays are arranged, and 
with what admirable symmetry they dovetail into 
each other. More regular figures cannot be de¬ 
scribed, and yet they are somewhat different in each 
kind of Agaric. In a basketful of such funguses, no 
two species are quite alike, but they agree in being 
all symmetrical, and eminently beautiful in the ar¬ 
rangement of their parts. 
37. Fungi of a much more simple structure continue 
to illustrate the same fact. There is a fungus called 
Sphccria militaris. In the West Indies is found a 
great wasp-like insect called a Pollstes. Out of this 
grows the fungus which destroys the creature, vul¬ 
garly named a Vegetable Wasp. If we observe, first, 
the shape of the fungus, and then examine its section, 
we find it covered by equidistant holes, which indi¬ 
cate the places whence the seed proceeds. Fvery 
hole represents the mouth of a cavity, all the cavities 
are arranged round a common centre, are all directed 
upwards at a particular angle, and are so placed be¬ 
tween each other that no one of them interferes with 
its neighbour, but each balances some corresponding 
cavity opposed to it. 
