BY JOHN MCLUCKIB. 



325 



stained with (a) earbol-gentian violet, Lugol's iodine and safranin, or (6) carbol- 

 fuchsin, or (c) in Loffler's stain. The bacteria wer-e clearly differentiated from 

 the cytoplasmic contents and starch grains. Text-figs. 8-12 show different 

 groupings of the bacteria in cells of the cortex of infected roots; sometimes the 

 bacteria are distributed generally throughout the cells or are aggregated at one 



Text-figs. 8, 9, 10, 11.— Cells of cortex of tubercle with the bacteria 

 (b) arranged in various ways. Sometimes the bacteria 

 occur throughout the cell, at other times they are ar- 

 ranged in zoogleal-threads which appear to pass from cell 

 to cell, (x 465). 



Text-figs. 12, 13. — In these figures a mass of bacteria is shown aggregated 

 around the nucleus of the cell, (x 666). 



Text-fig. 14. — A group of meristematic cells containing a large nucleus 

 (n), abundant granular cytoplasm (c), and many small 

 spherical starch-grains. These cells have no bacteria, 

 (x 666). 



end or crowded round the nucleus; at other times they form long, irregular 

 zooglea-threads frequently continuous with corresponding threads in adjoining 

 cells. The width of the threads varies, even in adjacent cells. These zooglea- 

 threads are very similar to those present in leguminous nodules and in the Podo- 



