CHAPTER III. — SPORES OF FUNGI. 



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if kept dry it will continue to adhere to the gonidiophore. Spores abjointed 

 close together in large numbers cohere through the coalescence of their gelatinous 

 envelopes and form masses which break up again in water. In the case of spores 

 successively abjointed on the free apex of one or several closely adjacent sterigmata, 

 if the development takes place without interruption in a damp atmosphere, the 

 gelatinous substance deliquesces and forms a spherical drop, in which the spores 

 lie embedded as in a vesicle. And all this occurs alike in those cases where the 

 successive abscision affects spores arranged in rows (gonidia of Nectria Solani 1 ) 

 and in those where they are in heads (Acrostalagmus cinnabarinus, gonidia of 

 Claviceps and Epichloe). Where abscision of large numbers of spores takes place 

 inside narrow receptacles provided with narrow orifices, their release from the 

 receptacle is effected by the formation of a gelatinous or gummy substance which 

 swells in water and emerges with the spores from the 

 receptacle. Examples are to be seen in numerous gonidia- 

 receptacles in the Pyrenomycetes. See Division II. 



A description of the development of the spore-chains 

 in the aecidium of Chrysornyxa Rhododendri' 2 will show 

 the mode in which the spores are shed in the Uredineae 

 by the solution and disappearance of a stalk-cell or in- 

 termediate cell beneath each spore. The spores in each 

 chain are formed by successive abjunction at the upper 

 extremity of a short club-shaped basidium, from which 

 at first an almost cylindrical spore-mother-cell is abjointed 

 by a plane transverse septum. This cell, which is about 

 one and a half times longer than broad, subsequently 

 changes its shape ; one side bulges considerably, the 

 other only slightly, and the whole cell thus becomes 

 irregularly barrel-shaped. It is then divided into two 

 unequal daughter-cells by a plane partition-wall which 

 runs from the angle formed by the basal cross septum 

 and the more prominent side obliquely towards the 

 flatter side, cutting off the lower third part of it ; the 

 lower of the two daughter-cells is a small wedge-shaped 

 stalk-cell or intermediate cell, the upper is larger and 

 developes into a spore. The spore is at first of a some- 

 what complex and irregular form, as is sufficiently apparent 

 from what has been said above and from the Fig. y]. It 

 increases considerably in size, assuming in so doing a 

 nearly spherical or ellipsoid figure, and becomes invested 

 with a new membrane of considerable thickness, into the 

 structure of which we must not at present enter. The stalk-cell grows at the same 

 time in height and breadth, remaining much lower on the side where its wedge-form 

 thinned out originally than on the opposite and now convex side, and has an 

 elliptic transverse section. Ultimately the stalk-cell disappears, its membrane and 

 the outer primary lamellae of the membrane of the mother-cell and of the transverse 

 septum swell up, become gelatinous, and finally vanish entirely with the cell-contents, 

 and the spores are now isolated. The division into stalk-cell and spore is usually 

 found in the third youngest spore-mother-cell on a basidium, more rarely in the fourth 

 youngest. The gelatinous dissolution of the stalk-cell is usually far advanced in the 



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FIG. 37. Chrysornyxa Rhododen- 

 dri. Basidium with a chain of spores 

 from an aecidium ; explanation in 

 the text. Magn. 600 times. 



1 De Bary, Kartoffelkrankheifc, p. 41. Reinke unci Berthold, Die Zersetzung d. Kartoffel durch 

 Pike, p. 39. 



2 Bot. Ztg. 1S79, p. 803. 



