CLASSIFICATION OF PARASITES AND SAl'lK -I'll YTK-v 7 



as hemi-parasites. They must, however, be included amongst 

 the hemi-saprophytes, because doubtless they are capable of 

 going through their whole development as .-apmphytes. The 

 hemi-parasites include, amongst others, the Vstilagineae, all of 

 which live for a time as parasites, and cannot, even by artificial 

 cultivation, be made to complete their life-history as >aprophyte-. 

 While, however, many of the I'stilagineae are adapted to a com- 

 pletely parasitic life, others can, in the form of sprouting conidia, 

 live and multiply saprophytically. The conidia of .n,/,,tx ;///////// 

 and Rnmxciis continue to bud off conidia for a considerable time 

 in nutritive solutions, yet in nature, the spores probably produce 

 infecting hyphae at once, and the fungus is but little suited to 

 sustain a saprophytic mode of life. Phytophthora inf-xtim* i> 

 more easily reared as a saprophyte, and occurs in nature as such, 

 hence it approaches somewhat towards the hemi-saprophytes. 



True Parasites. 



The Uredineae may be taken as the most typical of the true 

 parasites: they constantly pass through their whole life-histoi\ 

 on living plants, and cannot lie cultivated on a dead substratum. 

 So also the Erysipheae, although frequently their spores only 

 reach maturity on a dead substratum, as do also tho.-e of 

 /,'//////x///" and J'ii/i/sfi;/iint. Ergot of urain and the ,s',Y, /W//MC 

 inhabiting berries, are also truly parasitic, even though their 

 apothecia or perithecia are produced from hibernating sch-rotia. 

 and though their conidia can be >api ophytically cultivated on 

 dead pabulum. 



The Peronosporeae and I'rotomyce.s are also true parasite-. 

 In many (jther forms the development of germ-tubes, or the 

 -]. routing of conidia, may be obtained in artificial nutritive 

 solutions by exclusion of rival fun-i and bacteria, yet ii is 

 doubtful whether this takes place in nature. 



a. MODI-: OK UKK OK TIII-: PARASITIC FUNGI. 



Tin- p;ir;isitic fun-i may b.- divided aceordin^ to the plarr i 

 their occurrence and their mode of attack on the ho-t, into two 

 Categories, which may be designated epiphytic and eiidophytic 



