8 FUNGI. 



permeate the tissues of plants attacked by parasitic fungi, or 

 they run over dead leaves forming whitened patches, formerly 

 bearing the name of Himantia, but really the mycelium of some 

 species of Marasmitis. If checked or disturbed, the process 

 stops here, and only a mycelium of interwoven threads is 

 produced. In this condition the mycelium of one species so 

 much resembles that of another, that no accurate determination 

 can be made. If the process goes on, this mycelium gives rise 

 to the stem and cap of an agaricoid fungus, completing the 

 vegetative system. This in turn gives origin to a spore-bearing 

 surface, and ultimately the fruit is formed, and then the fungus 

 is complete ; no fungus can be regarded as perfect or complete 

 without its reproductive system being developed. In some this is 

 very simple, in others it is as complex. In many of the moulds we 

 have miniature representatives of higher plants in the mycelium 

 or roots, stem, branches, and at length capsules bearing sporidia, 

 which correspond to seeds. It is true that leaves are absent, 

 but these are sometimes compensated by lateral processes or 

 abortive branchlets. A tuft of mould is in miniature a forest of. 

 trees. Although such a definition may be deemed more poetic 

 than accurate, more figurative than literal, yet few could believe 

 in the marvellous beauty of a tuft of mould if they never saw it 

 as exhibited under the microscope. In such a condition no doubt 

 could be entertained of its vegetable character. But there is a 

 lower phase in which these plants are sometimes encountered ; 

 they may consist only of single cells, or strings of cells, or threads 

 of simple structure floating in fluids. In such conditions only 

 the vegetative system is probably developed, and that imperfectly, 

 yet some have ventured to give names to isolated cells, or 

 strings of cells, or threads of mycelium, which really in them- 

 selves possess none of the elements of correct classification — the 

 vegetative system, even, being imperfect, and consequently the 

 reproductive is absent. As already observed, no fungus is per- 

 fect without fruit of some kind, and the peculiarities of structure 

 and development of fruit form one of the most important elements 

 in classification. To attempt, therefore, to give names to such 

 imperfect fragments of undeveloped plants is almost as absurd 



