FUNGI. 318 
when the fructification consists of naked spores, 
and a multiple of four when it is contained in 
tubular cases or asci. Along with the basidia or 
formative cells of the hymenium occur large 
sterile cells, flask-shaped, and containing granular 
matter exhibiting molecular motions when dis- 
charged. These are called cystidia, and were 
supposed to represent antheridia, but they are 
now ascertained to be mere abortive basidia. 
Just as the petal or carpel of a flowering plant 
changes abnormally into a green leaf, so the 
cystidia of the mushroom abandon the reproduc- 
tive and return to vegetative functions by a sort 
of hypertrophy. 
While upon the subject of spores I may mention 
here that the remarkable elastic force with which 
many of the fungi eject their seed has often ex- 
cited attention, and is fully equal to anything 
of the same kind observed among flowering 
plants. In hot-houses, adhering to decaying 
leaves, may occasionally be seen a curious little 
plant called Spherobolus stellatus (Fig. 30), which 
bears no inapt resemblance in its shape and 
functions toa Liliputian mortar. It is of a pale 
straw-colour, and consists of two coats, both 
stellated, and separated from each other by a 
bead of dew exuded by the plant. The rays of 
the outer case are orange. No sooner is the inner 
