32 Natural History Bulletin. 



which occur only as associated with certain algae, (green 

 plants of lowly habit and structure), hardly as parasites for 

 the parties to the strange union seem, in many cases at least, 

 not to interfere with the well-being of each other. The struct- 

 ures resulting from this union are known as lichens, and were 

 until recently considered a distinct group of plants, quite as 

 distinct as the fungi themselves. 



In structure fungi, though always to be classed among the 

 simpler organisms, exhibit the greatest diversity. Some 

 consist of but a single cell, others show a very considerable 

 amount of differentiation either in the modification of the indi- 

 vidual cell, or, of an aggregate of cells. Most are soft, perish- 

 able, ephemeral; some are dense, hard, enduring; all fail to 

 reach the differentiation of distinct tissues and groups of tis- 

 sues, such as appear in the higher plants. 



Nearly all fungi consist w^hen at maturity of two distinct 

 parts; the first, the nutrient portion or myce/m7>i, made up usu- 

 ally of minute cobwebby threads,* more or less aggregated, 

 spreading upon or through the substance affording nutrition;, 

 and, second, the fruit-bearing portion, sfiorocarf ox fnictifica- 

 tion. 



This latter part, the fructification, often in popular estimate 

 passes for the fungus entire. 



In their reproduction fungi are all sporiferous, /. e. all have 

 spores, usually single cells, which when set free from the par- 

 ent plant become under favoring conditions propagative. 

 Fungi, as other plants are known by tiieir fruits, — by their 

 spores and sporocarps. 



AH our more conspicuous saprophytic fungi belong to the 

 order Basidiomycetes, complete definition of which, must for 

 lack of plates, at present be deferred. It is sufficient to say 

 that the spores are in this order produced by simple abstriction 



I The mycelial threads are in reality so many most thin-\valled and delicate 

 tubular cells called /lyf'uie, and the sporocarps are aggregations formed by the 

 compact interweaving of the threads modified in various ways to meet varied 

 purposes and conditions, — to adapt the plant to its position in the -world. 



