26 Transactions British Mycological Society. 



ships amongst the fungi, largely because their vegetative 

 characters, being almost valueless as a criterion of relationship, 

 cannot be used as in other plants and animals, to supplement 

 comparisons of reproductive organs. 



All workers on evolution have been struck by the marked 

 discontinuity of character both between different groups of 

 organisms and also within each group. This discontinuity is 

 one of the most marked features of living organisms, and it is 

 just as much exemplified in the fungi as in other groups of 

 organisms, but there is no more reason for supposing that the 

 liverworts have arisen from several different sources than that 

 the fungi have been so derived. 



Thus as against the opinion that the fungi are organisms 

 which have come directly from the algae by the loss of photo- 

 synthetic power, arguments have been advanced in favour of 

 the view that the forms from which they came never possessed 

 this power. Organisms which lose such an important character 

 as chorophyll are invariably strictly limited in their power of 

 development, whereas no group of organisms shows more diver- 

 sity of species than do the fungi. The fungi, possessing some of 

 the original impetus of primitive life, have evolved along their 

 own lines, and have achieved entirely novel types of repro- 

 ductive mechanism. To elaborate a new style of architecture is 

 not the mark of a decadent civilisation, and the fungi having 

 achieved so much that is unique in the plant kingdom cannot 

 be looked upon as a degenerate race. When the fungi are spoken 

 of as an insignificant race with no power of independent de- 

 velopment, I am reminded of a book I read in boyhood, namely, 

 Jules Verne's " Journey to the centre of the earth." It will be re- 

 membered that, with the novelist's imagination, he represents 

 the voyagers in the interior of the earth as having to traverse 

 a gigantic mushroom forest where fungi had achieved an 

 arborescent habit of growth. Jules Verne at any rate was alive 

 to the possibihties of fungi, and his outlook is to be preferred 

 to that which holds the group to be devoid of initiation and 

 crippled by degeneracy. 



The Relation of Mycology to Plant Pathology. 



As most plant diseases are caused by fungi, the relation of 

 mycology to plant pathology is clearly of great importance. An 

 accurate knowledge of pathogenic fungi is indispensable to 

 anyone who attempts to deal with the more general aspects of 

 disease in plants or with its control. Mycology is one of the 

 foundation stones of plant pathology, and indeed Berkeley and 

 de Bary, both eminent mycologists, were the real founders of 



