Download PDF

288 ZYGNEMATACEAE
PLATE XXII
Spirogyra
Fig. I. S. varians, gametangia, zygospores, and inflated sterile cell
from central Illinois. Fig. 2. S. bicalyptrata, gametangia and zygospores
from Czechoslovakia. After Czurda. Fig. 3. S. circumlineata, gametangia,
zygospores, and sterile cell from central Illinois. Fig. 4. S. jennicu, lateral
and scalariform conjugation, and zygospores from Szechwan, China. After
Jao. Figs. 5-6. S. parvula, scalariform and lateral conjugation, and an
aplanospore from central Illinois. Fig. 7. S. supervarians, gametangia and
zygospores from Cape Town, South Africa. Fig. 8. S. borgeana, gam-
etangia and zygospores from Illinois. (See also Fig. 16, PI. XXIII.) Fig. 9.
— S. subsalina, gametangia and zygospore from Finland. Figs, io-ii.—5.
gibberosa, lateral and scalariform conjugation, separation of receptive gam-
etangia, and zygospores from Szechwan. After Jao. Fig. 12. S. catenae-
jormis, scalariform and lateral conjugation, and sterile cell from central
Illinois. (See also Fig. 16, PI. XXIV.) Fig. 13. S. bullata, zygospores,
gametangia, and sterile cells from Szechwan. After Jao. Figs. 14-18.—5.
pratensis, vegetative cells, aplanosjwres, and zygospores. Note growth of
cells during development of aplanosporangia of which there are two extreme
types, also the bullate type of sterile cells. Type material from Charleston,
Illinois.