4 71 
than a year old and these have failed to show the production of any 
form other than the Diplodia. Eight months ago some material was 
received from West Africa at the Jodrell Laboratory, Kew Gardens; 
this material consisted of a stem of the cacao plant which had been 
badly attacked by Diplodia and on which the fungus was producing 
abundant perithecia grouped in stromata. Some of this material was 
selectd and placed in a sealed jar. An examination at the end of six 
months showed that the fungus was passing into an ascigerous condi- 
tion. The formation of the asci in the same stromata as had previously 
borne spores of Diplodia , coupled with the fact that asci could be 
observed in process of formation in some of the perithecia on a 
stroma while other perithecia on the same stroma had not yet got rid 
of ail of their Diplodia spores, left no room for doubt that it was the 
ascigerous condition of the fungus. 
From the mode of arrangement of the perithecia and from the 
nature of the stroma, asci and spores, the fungus has been classified 
in the genus Thyridaria, Saccardo (Sphaeriaceae, Phaeophragmiae) 
and has been named Thyridaria tarda, n. sp. The following 
diagnosis of the fungus is here given: — Peritheciis monostichis, 
stromate atroerumpente villosulo semi-immersis (3-7), ostiolo minuto; 
asci cylindraceo-clavatis sessilibus, 90-ioox 12 microns, paraphysibus 
flOO-130 microns longis) copiosis filiformibus obvallatis ; sporidiis 
oblique monostichis, oblongatis, fuligineis, triseptatis, leniter con- 
strictis, 19-20 x 6-7 microns. 
Diplodia { Lasiodiplodia ) pycnidicus status est : Sporis ellipticis, 
utrinque obtusis, uniseptatis, haud constrictis, fuligineis 24-27 x 13-15 
microns. 
{ Translated ). Perithecia monostichous, semi immersed (3-7) in a 
black erumpent stroma bearing a covering of weak hairs, having a 
minute ostiole, asci cylindrical-clavate, sessile, 90-100 x 12 microns 
surrounded by abundant filiform paraphyses (100-130 microns long) ; 
spores obliquely monostichous, oblong, fuliginous, 3-septate, slightly 
constricted at the septa, 19-20 x 6-7 microns, 
Diplodia (Lasiodiplodia), is the pycnidial form Spores elliptical 
obtuse at both ends, uniseptate not constricted, fuliginous, 24-27 x 13-15 
microns. 
The Diplodia form is esentially the form which is destined for 
rapid reproduction of the fungus It does not appear to pass readily 
into the ascigerous condition, as is evidenced by the failure hitherto 
to reproduced the ascigerous condition in artificial media. This is, 
however, not infrequently met with in the conidial and pycnidial 
forms of ascigerous fungi in the tropics. 
The life-history is, however, not yet complete ; it is still necessary 
to trace the development of the ascospore. This work is being con- 
tinued and will be published when it is completed along with an 
account of the disease more especially as affecting lli Para rubber 
plant. 
