nmm sP

THE BRITISH SMUT FUNGI 89
FIG. 13. Spoie geimination in Schioeteria. a. S. delastrina. x200 (Brefeld, 1883);
6. S. delastrinaT X 340 (Cocooni, 1898).
On Veronica arvensis.
Norfolk (Fakenham, June, 1889, Plowright, Trans. Brit, mycol. Soc, i, p. 60,
1899; BrundaU, 21 June, 1945, E. A. Ellis); Oxon. (Peppard Common, May,
1943, L. E. Hawker, ibid, xxvii, p. 48,1944 [Herb. I.M.I. 32336]).
Spore germination. Schroeter (1877) germinated spores from Veronica arvensis.
Only one of the paired spores produced a germ-tube. Three days after sowing
this was 2-5 /x thick and about five times the diameter of
the spore in length, septate, and usually branched. Eggshaped
sporidia (5-6 X 3 ft) were formed at the end of the
promycelium. Brefeld (1883) illustrated the germiuation of
12 pairs of spores (from Veronica arvensis or V. triphyllosl).
Sometimes both spores germinated. The promycelia were
septate, relatively long, of uniform thickness, and nearly
spherical sporidia developed in a chain from the apex
(Fig. 13 a). Winter (1876) figured a promycelium with one
short side branch and one longer, septate ^filament bearing
FIG. 14. Schroeteria
delastrina. Spores.
X500.
three apical branches. Cocconi (1898) investigated the form (described as
var. reticulata) on Veronica praecox. In some spores the germ-tube formed a
much-branched mycelium, in others round, sporidia developed basipetaUy in
chains on a simple or forked promyceUum. One spore was figured with a
terminal crown of short branches as described by Winter (Fig. 13 6).
The related Schroeteria decaisneana from Veronica hederifolia was described
and figured by Schroeter (1877). A peculiar feature of this species was the flaskshaped
promycelium (width 3-4 /u. at base) from the neck of which developed a
succession of globular sporidia (2-5-3 /x). These sometimes remained in a chain
of four to seven. Their subsequent behaviour was not determined.