CHAPTER XLVII. 

 FURTHER STUDIES ON NUTRITION CONCLUDED. 



608. Nutrition of moulds.- 



Fig. 424, 

 Carnation rust on leaf and flower stem 

 graph. 



higher plants and derive tlieir food materials lit 

 pense. Such a fungus is called a parasite^ and there 



In our study of mucor, as we h.tve seen, the 

 growing or vegetative pai-t 

 of the plant, the mycelium, 

 lies within the substratum, 

 which contains the food 

 materials in solution, and the 

 slender threads are thus 

 bathed on all sides by thenn. 

 The mycelium absorbs the 

 watery solutions throughout 

 the entire system of ramifica- 

 tions. When the upright 

 fruiting threads are devel- 

 oped tltey derive the materials 

 for their growth directly from 

 the m}'celium with which 

 they are in connectic>n. T!ie 

 moulds which grow on de- 

 caying fruit iir on other 

 ort;anic inatter derive their 

 nutrient materials in the same 

 wa\". The portion of the 

 mould ^\■hich \\e usually see 

 on the surface of these sub- 

 stances is in general the fruit- 

 ing part. The larger part 

 of the mycelium lies hidden 

 witliin the subtratum. 



609. Nutrition of para- 

 From photo- sitic fungi.— Certain of the 

 fungi gm\\- on or within the 

 them and at their ex- 

 are a large number 

 322 



