264 
THALLOPHVTES. 
a broad cake as in the * flowers of tan/ or weak ascending outgrowths which gradually 
assume the form of the mature fructification, usually a stalked spherical or club- 
shaped body, or a spiral tube ^, the growth of which is generally completed in a few 
hours. It has already been mentioned that the ripe fructification is usually sur- 
rounded by a firm wall, and that it often contains the so-called capillitium, in the 
interstices of which lie the numerous spores. Neither the wall of the fructification 
nor the capillitium is composed of cellulose, nor is the fruit-stalk, which is usually 
hollow; it must rather be supposed that the substance of the Plasmodium, after it 
has already assumed the external form of the fructification, becomes differentiated 
into two distinct substances, one of which becomes hardened in various ways into 
pellicles, tubes, and solid threads, and thus forms the stalk, the wall of the fructifica- 
tion, and the capillitium, while the rest of the protoplasm, which has the capacity 
of further development, breaks up into small round portions which become invested 
with cell-walls and thus form the spores. The substance of the wall and of the 
capillitium corresponds, therefore, as Brefeld has pointed out, to the mass capable 
of swelling which fills up the space between the conidia in the conidiophore of the 
Mucorini. In the process of free cell-formation also by which the ascospores of the 
Ascomycetes are produced, there often remains within the ascus a considerable portion 
of its contents which is obviously not adapted to enter into the composition of a spore 
capable of germination. 
In the differentiation of the protoplasm of the plasmodium into spores and into 
those portions (capillitium and wall of the fructification) which take no part in the 
further development, other portions of the contents which are useless for purposes of 
reproduction also become eliminated, and especially lime, which is often excreted in 
large quantities in the form of fine granules of calcium carbonate, and the yellow sub- 
stance which coats in loose flakes the fructification of the ' flowers of tan.' 
It must be added in conclusion that under favourable vital conditions both the 
separate zoogonidia and the young or old plasmodia pass into a resting-state, the former 
simply becoming invested by a cell-wall, the latter becoming transformed into masses 
of cells ^. 
B. Conjugation takes place between stationary cells. 
In the Zygomycetes^ the vegetative body, which, as in all Thallophytes des- 
titute of chlorophyll (Fungi), is termed the mycelium, consists of a ramified hollow 
tubular cell (Fig. 174 B, m)^ in which septa only appear when it is fully mature and 
ready for sexual or non-sexual propagation. The ramifications of this mycelium all 
originate from a single germinating filament which is developed from a non-sexual 
reproductive cell (conidium), and may, in the course of a few days, cover with a 
^ The term Mthal'mm is given by Rostafinsld to those large fructifications produced by the co- 
alescence of several simple ones, and which are therefore syncarps, as in the case of ' flowers of tan.' 
2 On the Chytridinese, which are perhaps allied to the Myxomycetes, see Braun, Abhandl. der 
Berliner Akad. 1856, p. 22. — De Bary and Woronin, Berichte der naturf Gesellsch. in Freiburg, 1863, 
vol. III. Heft 2. — Woronin in Bot. Zeit. 1868, p. 81. [Sorokin (Bot. Zeit. 1874) has discovered in 
Zygochytriutn a process of conjugation resembling that of Mucorini, and in Tetrachytriutn a con- 
jugation of zoogonidia. Pfitzer (Monatsb. d. Acad. d. wiss., Berlin, 1872) includes ChytridiacecB with 
all the CoeloblastcB destitute of chlorophyll in one group, the Phycomycetes. Sorokin suggests the 
name Siphomycetes for this, of which Amcebidiujn (Cienkowski, Bot. Zeit. 1861) is to be regarded as 
the simplest form.] 
2 Brefeld, Botanische Untersuchungen über Schimmelpilze, Heft i, 1872. — Van Tieghem, Re- 
cherches sur les Mucorinees, Ann. des Sc, Nat., 5® ser., 1873, vol. XVII, and in the French translation 
of this work, p. 336 et seq. [Quart, Journ. Micr. Soc. 1871, pp. 49-76. — Ann. des Sc. Nat., 
6® ser,, vol. I, 1875, p. i.] 
