BY JOHN MCLUCKIE. 



303 



methyl violet. Vacuoles become less numerous in the hyphae which soon appear 

 densely charged with protoplasm or proteid. While as a rule the hyphae main- 

 tain their normal reg-ularity of width, occasionally I have seen hyphae which 

 were distinctly irregular in their diameter, especially near the end in association 

 with the nucleus (Text-figs. 16, 26). 



In certain cells which have been filled with the fungus for some time, the 

 highly nourished hyphae begin to disorganize. They become closely associated 

 and lose their individuality, forming a deeply-staining mass in the centre of the 

 hyphal tangle surrounded by numbers of lightly-stained normal hyphae, some of 

 which spread into other cells (Text-figs. 16, 17, 18, 19). 



The nucleus of the infected cell gradually enlarges until it becomes twice or 

 three times its normal size. The chromatin stains more deeply and indeed ap- 



Text-figs. 18, 19, 20.— Stages in the digestion of the fungal hyphae. In 

 Fig. 20 this is nearly completed, and starch-grains are re- 

 appearing in the cell (x 450) 



Text-figs. 21, 22.— Enlarged nuclei of host-cells, showing the irregular 

 shape and indentations of the nuclear membrane caused 

 by the pressure of the fungal hyphae (x 510). 



Text-fig. 23.— First hyphae growing into a cortical cell containing 

 starch. The appressorium-like structure of the hypha in 

 contact with the wall is indicated (x 450). 



pears more abundant; the nucleolus enlarges. The whole appearance of the 

 nucleus about this time is suggestive of a high state of nutrition. 



The shape of the nucleus is also irregular in infected cells, the membrane 

 being pushed in by hyphae growing in close contact with it (Text-figs. 21, 22). 



The cytoplasm of the host-cells still appears quite normal after the digestion 

 of the hyphae. Starch grains reappear during the disintegration of the fungus, 



