50 M. C. COOKE ON MICROSCOPIC MOULDS. 



evidence of this if we compare our own literature with theirs. 

 The splendid works of Corda and Tulasne have no counterpart 

 with us, except in the less ambitious Cryptogamic Flora of the 

 late Dr. Greville, and the forty years' unrequited labour of the Rev. 

 M. J. Berkeley. 



If we examine the decaying stems of herbaceous plants during 

 the winter or in the spring, it will not be long before we discover some 

 grey mould flourishing in patches, and giving off a cloud of spores 

 directly it is shaken or roughly handled. Just such a mould as I 

 have in my mind's eye I have found in little* tufts on a decaying 

 portion of the outer husk of the fruit of the Horse Chestnut. This 

 mould always ^ grows in tufts, visible to the naked eye, like a 

 miniature tuft of grey wool ; but if we employ a pocket lens for 

 closer examination, that instrument will be sufficient to reveal to 

 us a tuft of shining, dark coloured threads or flocci, supporting 

 clusters of little white spores. Even such an examination, imper- 

 fect as it is, cannot fail to impress the observer with the beauty 

 of the object ; but if we employ successively a microscope with a 

 two-inch, a one-inch, and a quarter-inch objective, by dint of 

 patience and perseverance we shall be able to make out the entire 

 structure delineated in the diagram. (Plate vi.) This mould is 

 known as Poh/actis fasciculata, and was first figured and described 

 by Corda in his " Prachtflora." The tuft of flocci or threads is 

 connected at its base with, and springs from, a reticulated mass of 

 delicate branched creeping filaments, which is called the mycelium. 

 This mycelium corresponds to the root of a plant, of which the 

 erect flocci represent the stem, giving off branches and bearing the 

 fruit in the form of clusters of spores. Fungi, in all the families, 

 more or less possess a mycelium ; it is the base of the vegetative 

 functions of the plant, and however much the complete fungus 

 may differ from others, there is a greater similarity in the character 

 of the mycelium than in any other organ. Sometimes it happens 

 that only a mycelium is produced, growth being checked, and de- 

 velopment going no further. At other times barren threads spring 

 from the mycelium, but produce no fruit. In both such instances 

 the plant is imperfect, and it can only be guessing to say what 

 species it might have been had it matured itself. Persons who 

 know nothing of fungi are apt to jump to the conclusion that 

 Mycologists can or ought to be able to give some name for the 

 mycelium or barren threads of any fungus which is put into their 



