( XI ) 



in Lichens, certain conceptacles, which, though they had not 

 wholly escaped the attention of earlier writers, were first really 

 discovered, and their structure exhibited by Tulasne (Mem. 

 sur les Lich. pp. 129-235), who gave them the name of Spermo- 

 gonia. These organs, for the most part very minute (but to 

 this there are exceptions) are more or less rounded, and often 

 more or less blackish, but now of the colour of the thallus ; and 

 occur immersed in, or protuberant like little warts above, its 

 surface j and open (like the Verrucariaceous apothecium, as also 

 like the young Parmeliaceous, with which, in some lichens they 

 may be confounded) by a pore at the summit. The interior of 

 the conceptacle is thickly clothed with converging filaments 

 (sterigmas} which were considered as giving rise to, and as 

 supporting little, more or less spore-like bodies found within 

 the spermogonium, and called spermatia, The sterigmas are 

 either elongated-cylindrical developing most commonly into 

 branched, series of cells, or similar branched series of cells 

 scarcely longer than broad (arthrosterigmas). The spermatia 

 are either ellipsoid, or oblong, becoming staff-shaped (the most 

 common form) or needle-shaped, the last often bowed. Nylander 

 has made much systematic use of the differences in the sterigmas 

 and spermatia, even in the limitation of genera ; but the latest 

 observations appear to confirm earlier ones that the latter organs 

 may vary considerably in the same species ; while it will be seen 

 that the sterigmas are not always satisfactory as criteria- 

 Beside Tulasne, Nylander has treated the spermogones and 

 their contents in great detail (1. c. p. 40) and they are the object 

 of a very extended investigation by Lindsay (Trans. Edinb. 22, 

 pp. 101-304). Their function has always been obscure. Accord- 

 ing to Tulasne (as cited by De Bary Morph. & Phys. d. PiU., 

 etc., p. 168, but there is scarcely anything in favour of the view 

 in the French author's above-cited memoir) and the earlier 

 opinion of Nylander (1. c. p. 40) the presumption that the sper- 

 matia are sexual organs, corresponding to the spermatozoids 

 of higher cryptogams, as the spermogones to the autheridia of 



