July 1904] 
Elementary Mycology 
177 
the leaf; they branch extensively and on each ultimate tip a con- 
idium is produced (Fig. 5). Other forms of conidiophores and 
conidia are found in various fungi (as “White Rust” of Shep¬ 
herd’s purse (Fig. 14) ; and the Leaf-spot, or Cercospora of Celery 
(Fig. 8). In case of the large group of Fungi to which the Toad¬ 
stools belong, the spores are borne on little pedicels (called ster- 
igmata) that arise from a large cell which is called a basidium 
Fig. 10. A small section from the gill of an Agaric, or Mushroom, showing the 
hyphse that terminate in Basidia which bear the spores. 
Fig. 11. Hyphse of the Mucor, or the common Black Mould, producing conidio¬ 
phores that bear the conidia in receptacles at the apex. 
(Fig. 10). Quite a different type of spore formation is seen in 
the common Black Mould. Here the sporophores are erect and 
develop within the enlarged terminal cell a multitude of conidia 
(Fig. 11). In other cases, for example, the fresh-water Alga 
called Oedogoniuni, the entire mass of protoplasm in a cell be¬ 
comes a spore, develops cilia, i. e., protoplasmic lashes or locomo¬ 
tive organs, and after escaping from the ruptured wall of the 
parent cell, swims about for a short time previous to permanent 
settlement and development into a filamentous form like the indi¬ 
vidual from whence it sprang. In case of Ulothrix, another of 
our common Algae, the protoplasm in a single cell becomes frag¬ 
mented into two or many ciliated individuals, or swarm spores, 
which likewise are very active immediately upon their escape. 
When they come to rest their cilia disappear and soon a filament 
of the usual type is developed (Fig. 12). 
Sexual Reproduction.— It is not always the case that the 
single reproductive cell developes into the usual parent form; 
instead, if often unites with another like or unlike cell and the 
result of this union is the spore — the so-called sexual-spore, 
which then at once, or after a resting period, gives rise to the new 
individual. The essential feature of this process, sexual repro¬ 
duction, is the fusion of the two nuclei of the gametes — as the 
two conjugating masses are called. The mechanism of the pro¬ 
cess is various in various groups of plants, but only a few illustra- 
