XU] ABOUT FUNGI. 183 
to end. At its summit it bears a string of round 
cells which, when separated from the plant, cannot 
be distinguished from Torula. These are the spores 
or conidia, which, if sown on an 
appropriate substance, send out 
shoots from various parts of the 
cell-wall. These shoots are at first 
simple elevations of the cell-wall, 
like the budding of Torula, but 
they continue to elongate by trans- 
verse division of the cells compos- 
ing them until a considerable ex- 
tent of surface is covered by their 
ramifications, These shoots are © 
termed hyphe, and the felt-like 
mass formed by their growth is known as the myce- 
lium. These hyphe send off branches above and 
below; those above, which are erect, are the aerial 
hyphae, whilst those below are the submerged hyphae, 
and serve the purpose of roots. The aerial hyphe 
bear upon their summits the conidia, which also are 
formed by the transverse division of the cells. It 
should be noted that, neither in this nor in any other 
form of fungus, do cells multiply by longitudinal 
division. 
Another form very similar to Penicillium is Mucor, 
but in this the hypha consists of an undivided tube, 
or a cell drawn out to a very great length. The 
aerial hyphe bear a large globular cell (the sporan- 
gium), which contains a large number of smaller cells 
(ascospores). These ascospores are set free by the 
bursting of the sporangium (or ascus, as we shall 
Fic, 135. 
