The ‘ Endoconidia’ of Thielavia basicola, Zopf. 
BY 
WILLIAM B. BRIERLEY, M.Sc., 
Pathological Laboratory , Royal Gardens, Kezv. 
With Plate XXIII and one Figure in the Text. 
Introduction. 
r HIELA VIA basicola , Zopf, is a parasitic fungus well known to 
plant-pathologists. The ascigerous fruit which is referred to the 
Perisporiaceae has only once been obtained in pure cultures of the fungus, 1 
and with this exception is connected with the other spore forms only 
by their association on the host plant and a doubtful tracing of continuity 
of mycelium. 
The best known condition of the fungus is the black ‘ torula * or 
chlamydospore stage, which was described by Berkeley and Broome 2 
as early as 1850. 
The interesting ‘ endospores ’ escaped attention until a quarter of 
a century later, when the fungus was very thoroughly investigated by Zopf. 8 
It is with this stage of Thielavia that I propose to deal in the present 
paper. 
Zopf describes these spores as being borne on short several-celled 
conidiophores and formed in acropetal succession. Their lateral walls then 
differentiate into two layers, of which the outer forms a sheath through 
which the conidia successively emerge. The cause of their extrusion is 
presumed to be a mucilaginous middle lamella which swells on access of 
water and so pushes out the spore. 
1 Peglion, V.: La moria delle piantine nei semenzai. Ricerche intorno ai mezzi de difesa. 
Staz. Sper. Agr. Ital., vol. xxxiii, fasc. 3, 1900, pp. 221-37. 
2 Berkeley, M. J., and Broome, C. E. : Notices of British Fungi: Torula basicola. Ann. and 
Mag. Nat. Hist., ser. 2, vol. v, 1850, p. 461. 
3 Zopf, W. : Thielavia , gen. nov. Perisporiacearum. Verhandl. Bot. Ver. Prov. Brandenburg, 
j. 18. Sitzungsber. 30. Juni 1876, pp. 101-5. Die Pilze, 1890, pp. 36, 8r, 96, 113, Fig. 61. Ueber 
die Wurzelbraune der Lupinen, eine neue Pilzkrankheit. Ztschr. f. Pflanzenkrankh., Bd. i, No. 2, 1891, 
pp. 72-76. 
[Annals of Botany, Vol. XXIX. No. CXVI. October, 1915.] 
