Lecture XII 



173 — 



Mycotrophic Phagocytosis 



Melin concluded: "The anatomical structure shows that the 

 higher symbiont suffers no injury from the fungal hyphae. Quite the 

 contrary, some of the hyphae are later digested, whereby the higher 

 symbiont obtains some nutrient while the fungus, through its haus- 

 torial hyphae, derives some nutrient-material from the higher sym- 

 biont. Finally, a nutrient-interchange takes place between the Hartig- 

 net and the palisade layer which long keeps both tissues alive". 



These descriptions inform us of the ectotrophic (or ectendo- 

 trophic, if we choose) mycorrhizae in Sweden. From the other polar 



Fig. 16. — Some cells from mycorrhizal cortex of 

 Fraxinus americana, in which the fungal reserve, 

 which overwintered, is largely broken down and 

 partaking of a plasma stain. Note enlarged nuclei. 



extreme, from the Cape of South Africa, comes an exactly similar 

 report. Smith & Pope (1934) state with reference to mycorrhizae 

 of Eucalyptus: All the main internal features (the layered mantle, 

 the palisade-like epidermal cells with "Hartig-net" mycelium) are 

 paralleled in Melin's descriptions of other tree mycorrhizae. The 

 fungus is usually present inside cells of epidermal layer and the 

 outermost cortical layer but rarely occurs in any deeper layer. Intra- 



