THE STRUCTURE AND LIFE -HISTORY 

 OF A FUNGUS. 



By HAROLD WAGER, 



Assistant Lecturer and Demonstrator in Biology, in the Yorhshire College, 

 Victoria University. 



The object of the present paper is to give an account of the 

 structure and life- history of a small microscopic fungus, scientitically 

 known as Peronospora parasitica, as a type of that group of plants 

 known as the Fungi. It is perhaps, in some respects, not 

 the best type for this purpose, yet it has the advantage of 

 having a comparatively simple structure and method of develop- 

 ment, easy to understand, and serving as an excellent introduction 

 to the morphological study of the Fungi. This type is also the 

 more interesting because many structural details, wliich are fully 

 described in this paper, have been more completely worked out 

 in it than in any other. 



Characteristic Features of the Fungi. 



The Fungi are mainly distinguished from all other plants by 

 the absence of chlorophyll, but they are further distinguished 

 by a distinct and characteristic mode of development, which is 

 even sufficient to separate them from the Algie — the group with 

 which they are most closely connected — apart from any considera- 

 tions as to the presence or absence of chlorophyll. Plants which 

 contain chlorophyll are able by its means to take up from 

 inorganic food substances all the materials which they require to 

 build up their tissues — transforming them during the process into 

 the extremely complex organic compounds which enter into their 

 composition. Fungi, on the other hand, owing to the absence of 

 chlorophyll, are unable to do this ; they require organic compounds 

 already prepared, and in consequence have to depend for their 

 food upon organic substances formed by other plants or by 



