Kelley — 126 — Mycotrophy 



(orchids), and phy corny cetous endotrophs as in the vesicular-arbus- 

 cular sorts. Since the terms "vesicle", "arbuscle" and "sporangiole" 

 have been adopted from the French, there seems no valid reason why 

 the term "peloton" should not also be adopted, to describe the endo- 

 trophic mycorrhizae of orchids and some other plants. 



Peloton Mycorrhizae: — In Neottia Nidus-avis, according to 

 W. Magnus (1900), the root-inhabiting fungi possess very few and 

 irregular connections with the outside. The 3-4 outermost layers 



Fig. 10. — Cross-section of endotrophic mycorrhiza of Acer 

 Negundo. Invading hyphae are coiled in the cortex. 



of cells beneath the epidermis are completely and without exception 

 inhabited by the fungus while in rhizome and stem even six layers 

 may be infested. Infected cortical cells are enlarged and later formed 

 cells are also enlarged, causing a change in the whole structure. Within 

 the cortex two sorts of cells were distinguished, "Pilzwirthzellen" 

 and "Verdauungszelle". According to Magnus, after the hyphae had 

 formed protein (Eiweisshyphen) their content was taken up by the 

 cell and the residue was pressed together, while at the same place or 

 at a place mostly lying in the middle of the cell there begins a local 

 clotting formation. They then become separated, with a portion of 



