DISEASE CAUSED BY FUNGI 195 



bearing plants with that of the fungi, the superiority of 

 the former from both a morphological and physiological 

 standpoint is at once evident, as compared with the fungi. 

 In both groups the primitive sexual generation as a 

 distinct and independent structure has gone in the higher 

 forms, but in chlorophyllose plants it was, as it were, 

 absorbed by the newer sporophyte generation, and its 

 primitive functional activity retained. It is this retention 

 of the means of sexual reproduction that has enabled the 

 sporophore generation of chlorophyllose plants to attain 

 their present development. Ample proof of this idea is 

 illustrated by the difficulty experienced in perpetuating 

 plants reproduced by asexual or vegetative methods alone, 

 as potatoes, etc. 



The fungi, on the other hand, through inability to incor- 

 porate the sexual phase with the new aerial conidiophore, 

 have failed to evolve morphologically beyond the primitive 

 hyphal element ; there is no vestige of a tissue, as under- 

 stood in phanerogamic structures, present in the highest 

 forms. The evolution of nuclear fusion, as demonstrated 

 by Dangeard, has saved the fungi from actually disappear- 

 ing, but it has proved incapable of enabling them to assert 

 themselves, thus demonstrating its inferiority as compared 

 with true sexual reproduction. 



II. PATHOLOGY 

 DISEASE CAUSED BY FUNGI 



Obligate parasites have been shown by Brefeld to be not 

 under all conditions absolutely dependent on the presence 

 of a living host for their development. He succeeded in 



