CHAPTER III. —SPORES OF FUNGI.—GERMINATION. Ill 
soon comes to an end; it elongates for a little while and then abjoints acrogenously 
at the expense of its protoplasm a small number of spores unlike the mother-spore, 
and itself soon dies away. The product of germination in this case bears the name 
of promycehum which was given to it by Tulasne, and the abjointed spores are 
termed sporidia (Fig. 55 A, B, Fig. 56). Both types of formation of germ-tubes are 
always peculiar to certain species and to certain forms of spores, on which point 
further remarks will be found in Chapter V; both behave alike in those first 
stages of their development with which we are concerned in this place. 
Taking the simple non-septate spore-cells first, we find the simplest formation 
of the germ-tube among swarm-spores. As soon as they have come to rest and are 
provided with a membrane, they grow out at one or two or even more points into a 
cylindrical tubular process the membrane of which is the immediate continuation of 
the membrane of the spore (Fig. 53.) In most of the non-motile spores the 
proceeding is essentially the same, but with this difference, that the tube is covered 
only by a delicate continuation of an innermost layer of the spore-membrane. It is 
uncertain whether in the case of these spores the whole of the spore-membrane is 
ever prolonged as the covering of the tube; 
even where the spore-membrane before ger- 
mination is delicate and without obvious separ- 
ation into endosporium and episporium, the 
delicate wall of the germ-tube may often be 
clearly seen to be continuous with the layer of 
the inner surface of the spore-membrane, as 
in Acrostalagmus, Penicillium, &c. Even: where 
an endosporium is stout its whole substance is 
not extruded to form the membrane of the 
germ tube, but only its innermost lamella, as in „porc Zerminating on the surface of water. The 
uredospores. The advancing germ-tube breaks ne een 
through the outer layers where the episporium, fine, ">"reelum sa sporidium Maem ap 
is strongly developed, causing them to open by 
valves or perforating them, and this either at spots not previously marked out by 
any special structure, or in places where pits were formed before the spores had 
matured and which were spoken of above as germ-pores. In a few cases the 
development of the germ-tube and the swelling of the inner part of the spore 
associated with it cause the layers of the episporium to break up into small pieces, 
as in Ascobolus sp., Diplodia sp.*, and some others. 
In some spores with a very stout episporium and a narrow germ-pore, as in 
Coprinus, Sordaria, and Chaetomium, the tube as it passes through the pore is a very 
slender protuberance, but immediately in front of the outer orifice of the pore it 
swells into a round and comparatively broad vesicle and after that grows on as a 
cylindrical tube, which may be branched or unbranched, a mode of growth which 
looks peculiar and has given occasion to strange misconceptions”, but is really 
nothing more than a special case not deserving any particular designation. 

FIG. 56. Rhytisma Andromedae, Fr. Asco- 

* Bauke, Beitr. z. K. d. Pycniden. 
? Bot. Ztg. 1866, p. 158. 
