CARPOSPORE^. 
of an angiocarpous fructification a peculiarly formed mass of tissue in which very 
large numbers of spores are produced, such a mass is termed a nucleus or gkba. 
The sexual organs, so far as they are known among the Ascomycetes, consist 
of a carpogonium as the female, and of a so-called poUinodium (antheridium) as the 
male. The two organs may differ but little in size and shape, and in Gymnoascus 
they are quite similar ; more commonly, however, the carpogonium is larger and is 
multicellular, whereas the poUinodium is a thin, usually branched, tubular cell. In all 
cases the carpogonium differs from the poUinodium in that from it alone the fertile 
hyphae take origin from which the spores are finally developed, the sterile tissue 
being derived from the hyphse bearing the carpogonium or even from neighbouring 
cells. 
Fertilisation is never affected by means of antherozoids \ but by the close appli- 
cation of the poUinodium in its whole length to the carpogonium, or merely of the 
apex of the poUinodium to the anterior portion of the carpogonium. Occasionally 
this portion of the carpogonium is prolonged into a narrow tube like the trichogyne 
of Nemalion. In the majority of the observed cases there is no direct exchange of 
protoplasmic substance between the poUinodium and the carpogonium in the process 
of fertilisation : the two organs remain closed and the fertilising matter passes from 
the poUinodium into the carpogonium apparently by diffusion. The fertile hyphse 
of the fructification arise usually not from that part of the carpogonium which has 
been in direct contact with the poUinodium, but from nearer its base. Here again an 
analogy with the formation of the fructification of Floridese presents itself. 
Histologically considered, the mycelium and the fructification of these Fungi 
consist of hyphse. The hyphae are multicellular, usually much-branched, filaments 
which grow at their apices, and are generally very long and thin. In many cases, 
even in the larger fructifications, as for instance in the Mushrooms, it is easy to 
make out the individual hyphae, but in other cases, although the tissue really consists 
of hyphae, a so-called pseudo-parenchyma is formed by the close aggregation of their 
short thick segments. In angiocarpous Fungi (Tuberaceae, Gasteromycetes) this 
pseudo-parenchyma is usually differentiated into well-defined concentric layers. 
Commonly, but' not universally, the cell-walls of the pseudo-parenchyma are not 
coloured blue when treated either with iodine alone, or with iodine and sulphuric 
acid, but in certain cases this colouration is produced by the action of iodine alone 
(Asci of Lichens). Starch, as also chlorophyll, is absent from all Fungi, and this is 
the more remarkable since starch is found in Phanerogams which possess no 
chlorophyll. 
Fungi grow exclusively upon organic substrata. Many grow in earth which is 
rich in humus or some other organic matter, others are parasitic upon and within 
animals and plants; this parasitism may present itself in the most varied manner, 
the most remarkable case being perhaps that which, as we shall hereafter see, occurs 
among Lichens. The mycelium usually buries itself in the nutrient substratum and 
can scarcely be separated from it, whereas the fructification comes to the surface. 
As I do not propose to give an exact systematic account of the innumerable 
^ [In Lichens the carpogonium is fertilised by non-motile antherozoids, termed spermatia, 
which resemble those of the P'lorideoe.] 
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