Lecture XII 



— 171- 



Mycotrophic Phagocytosis 



chromatin content of the nuclei often accompanied by deformation, 

 'clumping' of the mycelium about the nucleus, disappearance of the 

 sharp outlines of individual hyphae, and the gradual conversion of 

 the hyphal constituents from the region of the nucleus outwards, to 

 a structureless mass possessing strong stainability. The last stages 

 in the process are marked by shrinkage of the nuclei and disappearance 

 of the stainable contents. This intracellular digestion of mycelium is 

 a continuous process observable throughout the vegetative season from 

 early spring to> late autumn. The proportion of cells in the active 

 mycelial condition or undergoing digestion at any given moment 

 varies with the time of year, the age of the root, and possibly also 

 with the season and other external factors." 



Phagocytosis in Ectotrophic Mycorrhizae: — Laing (1923) 

 makes the statement that there is no evidence of digestion in ecto- 



pic. 15. — Portion of a longitudinal section through 

 a mycorrhiza of Pferidiitm aquilinum, showing a 

 plasmoptyse stage in breaking down of hyphae (Re- 

 drawn from LoHMAN, Univ. Iowa Studies in Nat. 

 Hist, V. 9, pi. II, fig. 10). 



trophic mycorrhizae of conifers. But the whole question of ecto- 

 trophism remains in doubt for if it is true, as Melin (1923) re- 

 marked, that in older researches the delicate intracellular hyphae may 



