'212 Morphology and Systematic Botany under [BOOK i. 



sexuality in a Mould, namely, the conjugation of the branches 

 of Syzygites. In the same year Nees von Esenbeck sowed 

 Mucor stolonifer on bread, and obtained ripe sporangia 

 in three days (Flora, 1820, p. 528); Dutrochet proved in 1834 

 (Mem. ii. p. 173) that the larger Fungi are only the sporo- 

 phores of a filiform branching plant, which spreads usually 

 under ground or in the interstices of organic substances, and 

 had been till that time regarded as a peculiar form of Fungus 

 under the name of Byssus. Soon after, Trog (Flora, 1837, 

 p. 609) carried these observations further ; he distinguished 

 the mycelium from the sporophore, and pointed out that 

 the former is often perennial and is the first product of the 

 germinating spores. He made an attempt to examine the 

 morphology of the larger sporophores, and showed that it was 

 possible to collect the spores of mushrooms on paper, and 

 that those of Peziza and Helvella are forcibly ejected 

 in little clouds of dust ; he also produced new proofs of 

 Gleditsch's statement, that the spores of Fungi are dis- 

 seminated everywhere by the air. Schmitz published in ' Lin- 

 naea,' between the years 1842 and 1845 excellent observations 

 on the growth and mode of life of several of the larger Fungi. 

 It was not unnecessary at that time to make it clearly 

 understood that the spores of Fungi reproduce their species 

 exactly. 



But the lower, the small and simple Fungi, those especially 

 which are parasitic on plants and animals, were the most 

 attractive objects in the whole field of mycology. Here were 

 difficulties in abundance, here were the darkest enigmas with 

 which botany has ever had to deal, here was new ground to be 

 slowly won by extreme scientific circumspection and foresight. 

 In these forms, as in the Algae, the first thing to be done was 

 to make out the complete history of development in a few 

 species ; but it was much more difficult in the Fungi than in 

 the Algae to discover what properly belonged to one cycle of 

 development, and to separate it from casual phases of develop- 



