70 DIVISION I.—-GENERAL MORPHOLOGY. 
The septum appears first as an annular ridge on the inner side of the lateral wall 
of the basidium, and grows slowly into a plate of considerable thickness which is 
convex on the side towards the basidium and correspondingly concave on the other, 
and shows the bluish lustre of gelatinous membranes under the microscope. When it is 
fully formed the apex of the basidium elongates to form a new gonidium. The 
new portion thus formed is close under the transverse septum. In correspondence 
with the subsequently rounded form of its apex it is from the first somewhat 
narrower than the septum, and by its elongation it separates the septum at its 
margin from the lateral wall of the basidium and carries it upwards with the goni- 
dium to which it belongs. Each gonidium accordingly has its slightly convex 
surface resting at first on its younger sister with the margin free, but attached to 
its apex by the broad middle portion. The gelatinous cross septum, to which 
the whole of the surface of attachment belongs, is continuous above with the lateral 
wall of the gonidium; and while this becomes slightly thickened as it developes, 
a membrane, which is not at first clearly defined, is formed on the inner surface 
of the septum and is also continued into the lateral wall which it resembles in 
appearance; this is the persistent basal wall of the goni- 
dium. At the same time the original gelatinous transverse 
septum begins to disappear from its margin inwards as if it 
melted away. There is now in all beyond the third and 
fourth youngest gonidia of a row only a quite narrow in- 
termediate piece in the middle connecting each with its 
younger sister. This piece is of about the same height as 
the original septum, but the bluish glistening substance in 
it dwindles from below upwards into a small plate which 
becomes continually thinner and remains attached to the 
wall of the gonidium to which it belongs. As this process 
goes on the intermediate piece becomes pale and very 
slightly refringent, and after persisting for some time in 
this state at length disappears. There is no reason for 
b 2 regarding this delicate intermediate piece as a part of an 
outside membrane which covers the whole gonidial chain 
FIG. 36 Penieitium glaucum. ike a sheath, as I formerly did. The single gonidia show 
@ young gonidiophore with the com- 7 
mencement of successive serial ab- no important changes after they are detached from the 
Sen. en gonidiophore beyond the thickening of their membrane 
are en wie alone already mentioned, which cannot be further pursued here. 
and glycerine. Magn. 600 times. Most of the propagative cells formed by acrogenous 
abjunction which have now been mentioned are detached 
by abscision in the manner described above, and, like the cells of Sprouting Fungi, 
they must become detached by disappearance of an original intermediate lamella 
just as is observed in Cystopus. Careful examination shows indications of this in 
almost all cases, but the, details of the proceeding are often difficult to follow on 
account of the too small size of the parts, yet it can be seen very distinctly, in spite 
of their small size, in the successive gonidia-rows in Eurotium and Penicillium, not- 
withstanding their minuteness (Figs. 35 4 and 36). Some further details may be seen 
in Zalewski’s treatise, mentioned at the end of this chapter. 
In a certain number of forms the separation is effected by the formation of a 
gelatinous or gum-like deliquescent substance both on the surface of separation 
and on the rest of the circumference of the spore. It must be supposed that this 
substance also is the product of an outer lamella of the spore-membrane which 
was not originally gelatinous ; but the minuteness of the objects prevents this from 
being certainly ascertained. With the ordinary amount of moisture necessary for 
the growth of Fungi the deliquescent substance absorbs so much water that the 
spore when abjointed is easily detached; a drop of water washes it away at once, 
