117 
slide cultures these stromata attain a diameter of 2 mm. in about three 
, po nidia 
covering the strom he gonidia — exactly with iliso of “the 
normal —— ‘hiodueed on the leav The stroma, after remaining 
for so me in ol, was alind: a vertical section showed the 
pre — of two pyenidia similar in shape to those already described, but 
differed in the almost total absence of colour from the ouier cells of the 
wall, and in the fewer number of concentric: layers composing it, only 
three being present. The umbonate apex did not project above the 
level of - stroma. 
The es germinated in a mme solution in a manner exactly 
similar = rede obtained from the leaves, and there seems to but 
whereas when the gonidia are placed on a dying leaf, where disinte- 
gration of the tissues has commenced, pycnidia are produced i in abundance. 
The above experiments show that the Cytispora is a true apgmphgtis, 
and will not —' itself on uninjured living vanilla leaves. i 
the time the Cytispora comp the whole 
of the sap and protoplasm has disappeared from the leaf, which is 
consequently dry and shrivelled, and so long as it remains in this 
condition no further fungal development takes place, but if the leaf is 
kept damp the Cytispora stromata produce perithecia from the central 
portion, which originate as follows. A Fev section through the 
central portion of the stroma shows a minute spherical weft of intricately 
interwoven hyphe, filled with granular "weg ume and completely 
surrounded by a e of slender, thin-walled, yellowish hyphæ some- 
what concentrically arranged ; the central weft appeared to be perfectly 
homogenous, and show o trace of an ascogonium or ** Woronin's 
hypha,” but the difficulty of obtaining a median rais and at. the 
right time may possibly account for the absence of any differentiation 
in the central weft. a some time the entire body retains its spherical 
form but continues to increase in size, due mostly to the increase in 
thickness of the aromit ik but also to some extent to the growth 
that portion nearest to the free surface of the stroma grows upwards 
in the form of a cone until it bursts through the eene At this stage 
the young perithecium is conical in out ine with a rounded base, the 
basal portion enclosing the spherical weft of hyphe, e bounding ‘wall 
being 6-8 cells in thickness, pseudoparenchymatous coni e in the 
upper portion the hyphs run in parallel rows. The t ee 
outer layers of the wall all round are at this stage differentiated | by th 
dark colour and greater thickness ot their walls, the walls of the Lor 
layers being colourless, very thin, an and containing granular protoplasm 
the apical portion of the — consisting of parallel ipie, 
