Kelley 



— 168 — 



Mycotrophy 



tex, showing swellings before it passes the cell wall and later branch- 

 ing to form terminal sporangioles which at first are filled with 

 spherules, and finally to a gummy mass. Nuclei of cells which contain 

 them are much larger than those of other cells nearby. Again, in 

 Begonia 7'obusta, the fungus produces sporangioles which at maturity 

 contain very fine granules which finally diffuse through the cell. In 

 Helicia (of the Proteaceae) large cortical cells are infected by hyphae 

 that form sporangioles and later free their content to form a gummy 

 mass. 



Fig. 13. — Portion of a section through mycorrhiza of 

 Abies balsamea indicating some of the mantle or myco- 

 clena to the right, and within, fungal hyphae and arbuscles. 



In Vitis (Petri, 1907) the intracellular mycelium shows the fol- 

 lowing development: (-Z) A net of fine hyphae is formed about the 

 starch grains, which are soon dissolved. (2) Nuclear elements in 

 the ends of these fine hyphae undergo a differentiation which recalls 

 the synkarion-phase of the basidia during karyogamy. (3) A great 

 quantity of proteinaceous material accumulates in the ends of these 

 hyphae. (4) By chemical transformation, these hyphal branches and 

 their content are gradually transformed into prosporidia. 



In asclepiads, Busich (1913) found a special sort of vesicle 

 termed a "glomerule" ; and she also found formation of vesicles out- 

 side the root. In Vinca (Demeter, 1923), penetration of the epider- 



