' 
6 DIVISION I.—GENERAL MORPHOLOGY. 
several sap-cavities (vacuoles), Comparatively large vacuoles are often separated 
from one another by thin films-of protoplasm, which in elongated cylindrical cells 
are not unfrequently placed across the cell, like transverse septa of cell-membrane, 
and this position has before now caused them to be mistaken for transverse cell- 
membranes', The greater part of the 86-94 per cent. of water, which Schlossberger 
and Döpping found in fleshy mushrooms, is to be placed to the account of the 
watery cell-sap. 
Errera discovered a remarkably large amount of glycogen in the cells of many 
Fungi. This substance permeates the protoplasm, renders it unusually refringent, 
and may be recognised under the microscope by this quality and by the charac- 
teristic reddish-brown colour which it assumes in the presence of iodine. It occurs 
especially in the asci of the Discomycetes and Truffles, but Errera found it also 
in the vegetative cells of some of these Fungi, of some of the Mucorini, and of 
certain Hymenomycetes, &c. 
Nuclei' are found in many cells connected with reproductive processes in. the 
Fungi, in asci for example and basidia, and their relations to the formation of daughter- 
cells are in some cases at least clearly understood; but there is some uncertainty with 
regard to the nuclei in the vegetative cells of the thallus, owing to their minuteness. 
On the one hand the presence of nuclei in the vegetative cells is probable where they 
have not been directly observed, because the reproductive cells which have nuclei 
are formed directly from vegetative cells and are distinguished from them only by 
their greater size, which may be the only reason why their nuclei are clearly seen, 
and because the nuclein which is characteristic of cell-nuclei has been shown by 
macrochemical methods to be present in cells, in which the presence of a morpho- 
logical nucleus is not or has not been certainly ascertained. In conformity with this, 
Strasburger with the help of colouring reagents detected nuclei in the cells of the thallus 
and in the spores of the Saprolegnieae, and Schmitz had previously asserted their 
existence in a number of other Fungi, as for instance in Oidium lactis, in the 
Peronosporeae, Mucorini, and Saccharomyces; to these may be added Penicil- 
lium glaucum (Strasburger) and especially the gonidial state of Peziza Fuckeliana 
(Botrytis cinerea). But on the other hand the objects under consideration, except 
in the Saprolegnieae, are of such minute size, that the satisfactory discrimination 
of true nuclei from other small bodies contained in the protoplasm, and like them 
perhaps rendered more distinct by colouring reagents, is extremely difficult, and 
can only be obtained after renewed investigations. The accounts in our possession 
make it distinctly probable that the protoplasm of the elongated vegetative cells of 
the Fungi which have been examined contains several or even many small nuclei, 
the division and multiplication of which is not in direct morphological connection 
with the vegetative cell-division. Only the short vegetative cells of Saccharomyces 
according to Schmitz are uninucleate. The reproductive cells to which we have 
referred above have one or more nuclei according to the species; the connection of 
the nuclei with the formation of daughter-cells, as far as it is known, will be described 
below along with the phenomena of reproduction. 
The protoplasm of the cells of the Fungi contain no chlorophyll or analogous 

* See Reisseck in Botan. Zeitg. 1853, p. 337. 
