2 
their apices. - These spores are, in- probably every species, of a 
characteristic shape, called ‘“‘ sausage-shaped,” viz. cylindrical, 
slightly curved, with more or less rounded ends. This shape is 
also met with not only in the spores of Naemospora, but in the 
ascospores of Valsa and the allied Pyrenomycetes. 
Cytospora was originally defined by Ehrenberg in Sylv. Berol. 
p. 28 (1818), as follows :— 
“Sporangium membranaceum aut grumosum ostiolo in- 
structum, includens massam spore er enpopy: demum. pene 
cirrerum aut globulorum forma)-erumpentem 
e stroma, varying from 0°25 to 2 mm. in diamet eter, is 
covered by the epidermis or periderm which it usually raises 
t 
pustular, enclosing one or more chambers (pycnidia), which are 
often imperfectly separated and irregular or sinuous in shape 
(loculi), but are sometimes distinct, more or less circinating and 
occasionally arranged’ round a central chamber or a’ black 
columella. When the stroma is exposed by the bursting of the 
covering layer, a disc is seen in which there are one or more 
black pores; occasionally the stroma contains only one s 
but if there are several they rig still open by a common. 
pore, or by separate apertur The spores are always small 
(varying from 3 to 10 @ in lageh); often very numerous,* nearly 
or quite hyaline, and in a damp atmosphere they issue from the 
pore in a slender curling tendril,t which may be caused by greater 
moisture to coalesce into a globule or to sink into a formless mass. 
As the tendril collapses, the colour of the spore-mass always gets 
deeper in tint. The colour mentioned in the descriptions is that 
‘of the freshly exuded tendril. Whether the spore-mass assumes 
the-shape ef a globule or a tendril, depends upon the moisture 2 
of the atmosphere rather than upon the nature of the fungus. ~ 
The spores are frequently described as “ straight or curved, - 
but this is nearly always an illusion due to the different postures 
in which they are seen. Ifa single spore, of the ordinary sausage _ 
shape, is watched while moving in water under a microscope, it 
may be seen to pass through three phases, as it presents itself 
in the three planes of space : like many Diatoms and Desmids, 
it has a (curved) profile-view, a (straight) face-view, and a (circular) 
end-view. ‘The same statement is true of the spores of many 
Dasyscyphae and other small Pezizeae, and the same mistake is 
often made in the description of them. 
The members of the form-genus Cytospora are probably all 
pycnidial stages (or “ spermogones ”) of those Pyrenomycetes 
which have sausage-shaped spores, such as Valsa, Valsella, and 
* Rostrup reckoned the number of spores in a single pustule of 
Cytospora Pini to be over 400 millions, and this is no exaggerated estimate. 
If the ma aterial is in good condition and not too old, but without 
tendrils, the spores cin tie used to exude by placing the lower end of 
the stick in tepid ast or by — putting a drop of water on the bark. 
