3878 REPRODUCTIVE ORGANS OF FUNGI.—PHYCOMYCETES. 
Section 2. RepropucTIVE ORGANS OF THALLOPHYTES. 
Tue Thallophytes may be divided into four large groups, 
ealled respectively, Fungi, Lichenes, Characeze, and Algz, in 
each of which again several subordinate divisions have been 
made. The general characters of the larger groups will be de- 
scribed hereafter in Systematic Botany. At present we have 
only to examine their reproductive organs, and of these even 
we can only give a general sketch ; but for fuller information on 
this subject the student is more especially referred to Sachs’s 
‘Text Book of Botany,’ as printed at the Clarendon Press of 
the University of Oxford. 
1. Func1 on MusHrooms.—To give a detailed description 
of the various modes of reproduction occurring in the different 
sub-divisions of this order would be beyond the scope of this 
volume, and we will therefore simply choose a few examples as 
types of the different methods by which reproduction may take 
place. For this purpose we will adopt the classification proposed 
by De Bary, according to which the Fungi are divided into the 
following groups, viz. :—(i) Phycomycetes, (11) Hypodermis, 
(ii1) Basidiomycetes, (iv) Ascomycetes, after which we shall give 
a short notice of the Bacteria, which are now generally regarded 
as an order of the Fungi, called Schizomycetes. 
(i) Phycomycetes.—As an example of this group we will 
briefly describe the life history of Cystopus candidus, a fungus 
which is commonly found growing upon Cruciferous plants. It 
resembles closely in its morphological phenomena Vaucheria (the 
life history of which is described under ‘ Algze,’ page 394), not 
only in respect to its unicellular mycelium, but also in its forma- 
tion of oogonia and antheridia. 
On examining a plant infested by Cystopus, it will be seen 
that the greatly elongated one-celled branched mycelium of the 
fungus (jig. 835, A), is interwoven, as it were, among the cells 
of its host, and draws nourishment from the latter by means 
of little rounded projections or bladders, known as haustoria, 
which penetrate the cell-walls of the host-plant. After vege- 
tating for some time in this manner, erect branches grow out 
beyond the surface of the epidermis, from which conidia are 
formed by a process of budding. (The term conidia, when used 
by us, indicates in all cases reproductive cells which are thus 
produced asexually.) From these conidia, when moistened with 
dew, rain, &c., zoospores are formed, and these settling down 
upon a similar plant will, under favourable circumstances, again 
develop the Cystopus mycelium. 
But Cystopus can also produce zoospores by means of a sexual 
process, which takes place in the interior of its host. The ends 
of certain filaments of the mycelium swell up, forming oogonia 
(fig. 835, A, og, 0g); whilst two club-shaped bodies, the anthe- 
