ss of clustered sporangia, to show habit of aggregation,
natural size.

_Tubifera ferruginosa_ (Batsch) Macbr., p. 206.

Fig. 8. A single spore, x 1400.

[Illustration: PLATE VII]

EXPLANATION OF PLATE VIII

_Diderma floriforme_ (Bull.) Pers., p. 143.

Fig. 1. Sporangia of various ages, x 5.

Fig. 1 _a_. Spore of the same species, x 1000.

Fig. 1 _b_. A capillitial thread, x 1000.

_Physarum polycephalum_ Schw., p. 95.

Fig. 2. The sporangia, x 10.

Fig. 2 _a_. Spores, x 750.

Fig. 2 _b_. Capillitium, x 750.

_Leocarpus fragilis_ (Dicks.) Rost., p. 112.

Fig. 3. Sporangia, x 6.

Fig. 3 _a_. A group of sporangia, natural size, to show habit.

Fig. 3 _b_. A single spore, x 1800.

_Physarella oblonga_ (Berk. & C.) Morg., p. 109.

Fig. 4. A single sporangium, x 8.

Figs. 4 _a_ and 4 _b_. Capillitium and spore respectively, x 900.

_Craterium leucocephalum_ (Pers.) Ditmar, p. 105.

Fig. 5. Sporangia, the first closed, x 10.

_Physarum sinuosum_ (Bull.) Weinm., p. 52.

Fig. 6. Plasmodiocarp, natural size; 6 _a_, x 4; see also Plate XIX.,
Fig. 15.

_Physarum virescens_ Ditmar, p. 61.

Fig. 7. Groups of sporangia, x 3 and x 8.

Fig. 7 _a_. Spores, x 750.

_Physarum viride_ Pers., p. 98.

Fig. 8. A single sporangium, x 25; 8 _a_, reverse.

Fig. 8 _b_. The same after spore-dispersal.

Fig. 8 _c_. Capillitium, x 750.

[Illustration: PLATE VIII]

EXPLANATION OF PLATE IX

_Physarum didermoides_ (Ach.) Rost., p. 78.

Fig. 1. Sporangia, x 15.

Fig. 1 _a_. A single sporangium open; shows calcareous capillitium, x
15.

Fig. 1 _b_. Spores, x 900.

_Physarum notabile_ Macbr., p. 80.

Fig. 2. A cluster of sporangia, x 15.

Fig. 2 _a_. A single sporangium open, x 15.

Fig. 2 _b_. Spores, x 900.

See also Plate XV., Figs. 2, 2 _a_, and the frontispiece.

_Physarum contextum_ Pers., p. 56.

Fig. 3. A group of sporangia, x 15.

Fig. 3 _a_. Spores of the same, x 600.

_Physarum cinereum_ (Batsch) Pers., p. 59.

Fig. 4. A group of sporangia, x 4.

Fig. 4 _a_. A single sporangium, x 20.

Fig. 4 _b_. Capillitium of the same, x 240.

Fig. 4 _c_. Spores, x 450.

_Physarum albescens_ Ellis, p. 86.

Fig. 5. Sporangia, x 5.

See also Plate XVI., Figs. 4 and 4 _a_.

Fig. 5 _a_. Spore of the same species, x 450.

Fig. 5 _b_. Capillitium of the same, x 240.

_Physarum serpula_ Morg., p. 49.

Fig. 6. Plasmodiocarps, about natural size.

Fig. 6