In this family the hymenium is enclosed in small fruit-bodies,
_perithecia_ (Fig. 120 _b_), which appear to the naked eye as small
dots. In shape they resemble a globe or a flask with a narrow mouth,
through which the spores are ejected (peronocarpic ascocarps).
Different kinds of reproduction--conidia, pycnidia (chiefly with
microconidia), chlamydospores, and perithecia--are found in the same
species. The various stages in the life-history of these Fungi are so
dissimilar, that formally they were considered to be different genera.
Ergot furnishes a very good example.
[Illustration: FIG. 114.--A small portion of an ovary attacked
with _Claviceps purpurea_ (_Sphacelia_).]
[Illustration: FIG. 115.--An ovary with the conidial stage of
_Claviceps purpurea_ (_Sphacelia_).]
This family may be subdivided into 3 sub-families.