THE PAGE OF NATURE. 73 



things can exceed in beauty, as microscopical objects, 

 the sporidia of many of the lichens. Some are bright 

 scarlet, others deep blue, and others green, olive, golden 

 yellow, or brown. 



Besides these true organs of fructification, the lichens 

 are furnished with other parts which possess the power 

 of reproduction. A great many species, placed in un- 

 favourable circumstances, seldom or never produce proper 

 receptacles of seed ; but this is no obstacle to their pro- 

 pagation, as their whole surface is covered with collec- 

 tions of free powdery grains, which germinate into new 

 plants wherever they are carried by the winds. There 

 are also present on some lichens spongy excrescences 

 which resemble minute trees ; and one peculiar genus is 

 possessed of tubercles which occur on the back part of 

 the frond, and are lodged in little cups which appear 

 empty as soon as they have fallen out. The recent 

 researches of the French lichenists, Tulasne and It- 

 zigsohn, have discovered another kind of fructification 

 which is very common and exceedingly interesting. 

 This consists of minute, blackish, elevated, somewhat 

 gelatinous points called spermagonia, occurring on 

 various parts of the upper surface of the thallus. 

 These resemble, in external appearance, the tubercular 

 apothecia of the Lecideas ; but their internal structure, 

 as shown in Fig. 8, is quite different. They consist of 

 little cavities or utricles opening on the summit by a 

 tiny orifice, and filled with a thin transparent mucilage, 

 in which is contained a number of linear filaments of 

 extreme tenuity, and somewhat curved, which vibrate 

 slowly in every direction. These curious bodies are 



