96 INTRODUCTION TO THE STUDY OF FUNGI 



concur in the reproduction of a single individual." This is not 

 a very neat definition, and not wholly accurate. " Not perfected 

 when immersed in water " is contradicted by the Saprolegnieae, 

 which flourish in water. In a footnote to the same volume 

 the subject is alluded to in the following terms : — "It is almost 

 impossible to draw up characters which shall in every case dis- 

 tinguish the three orders of Lichens, Algae, and Fungi. Indeed, 

 the more natural such orders are, the more difficult it is to 

 arrive at anything approaching to mathematical precision. 

 Thus, in general, Algae grow in water ; Lichens in air, drawing 

 their nourishment from the medium which surrounds each 

 respectively, and not from the matrix ; while Fungi are 

 nourished by dead or decaying organised matter, and have 

 therefore been styled Usterophytac. Yet, true as these facts are 

 in general, there are a few instances in which to a certain 

 extent they will be found incorrect according to the letter." 

 But a very large number of Fungi are not " nourished by dead 

 or decayed organised matter," but flourish upon and destroy 

 living organisms, both vegetable and animal. The most com- 

 pact definition was that which described Algae as cellular 

 aquatic plants which derive their sustenance from the water 

 in which they grow ; Lichens as cellular plants growing in the 

 air, and deriving their sustenance from the surrounding 

 medium ; and Fungi as cellular plants which obtain their 

 sustenance from the matrix on which they flourish. This 

 was the basis of the definitions given by Berkeley in his 

 Lntroduction to Cryptogamic Botany, published in 1857, 

 wherein he defines the Algals as " Thallophytes deriving nutri- 

 ment from the water in which they are submerged," and the 

 Mycetales, including both Lichens and Fungi, as " Thallophytes 

 deriving nutriment from the matrix or the surrounding air ; 

 mycelium more or less evident." Subdividing the latter, we 

 have Lichens described as " aerial, nourished by air and not 

 by the matrix, producing gonidia " ; and Fungi as " hystero- 

 phytal or epiphytal, nourished by the matrix, never producing 

 gonidia." If we proceed to apply the last definition— for we 

 are not concerned with the others — to the whole mass of 

 organisms now generally grouped under the Fungi, we shall 

 discover that it is inadequate. 



