2 G. MASSES OX BASIDIOMYCETES. 



was gradually evolved, which in course of time completely super- 

 seded the original structure, and gave to the fungi an individuality 

 which enabled them to rank as a distinct group; so different 

 from their original condition that, but for the unbroken chain 

 of connection with ancestral types, could not possibly hav^ been 

 traced back. 



This addition to their original structure consisted in the 

 gradual evolution of a second mode of reproduction, which has 

 come to be known as the conidial phase, in the life cycle of the 

 individual : a phase or condition quite supplementary to the 

 original form of reproduction, as presented by the Saprd- 

 legnieae, Peronosporse, and other ancient forms of fungal life. 

 As a rule the conidial condition is the first to appear, and 

 continues to produce in rapid succession, and in innumerable 

 numbers, throughout that portion of the season during which 

 conditions are favourable for the rapid growth of the fungus, 

 very minute, asexually produced reproductive bodies called 

 conidia. These conidia are capable of germination the moment 

 they are mature, and being readily dispersed by wind and other 

 agents, those that happen to alight on the proper substance 

 germinate at once, thus forming a new centre for the production 

 of conidia, which are often produced within a week of the period 

 of infection. By this method of reproduction the fungus is 

 enabled to rapidly extend its geographical area, provided sufficient 

 of the special matrix required by the fungus is present within 

 the range of dispersion of its conidia. From the above account 

 it can be readily understood how quickly a fungous disease spreads 

 when it has once gained a foothold, especially in those cases 

 where the food-plant or host occurs in great abundance, — for 

 example, in a field of coi-n, potatoes, etc. If farmers and 

 horticulturalists would only grasp this fact, and act in con- 

 formity with ascertained laws, the numerous ravages caused by 

 fungi, entailing a loss of millions of pounds annually, would cease 

 to exist in proportion to the intelligence employed in securing 

 the desired object. However, to return to the subject directly 

 under consideration : towards the wane of the season of activity 

 on the part of the fungus, the mycelium, or spawn, which earlier 

 in the season produced conidia, now gives origin either directly or 

 indirectly to the higher or primordial type of fructification. The 

 spores belonging to the last-named stage require a period of rest 



