218 
They are probably true hyphal fungi closely related to the Schinzia Alni of 
Woronin. c. Infected area. Only cell walls and the contained A/izobia are 
shown. d, Dwarfed root-hairs on tubercle. ¢, Normal root-hairs, one infected 
with Rhizobia. f. Vascular bundle. g, Starch-bearing area surrounding entire 
infected area. 
Fig. 2. Portion of infected area somewhat more magnified showing distribution of 
Infektionsfid-n, Nuclei and cell protoplasm are not shown. a. Cell filled with 
Rhizobia. d, infecting strands, 4, Infektionsfiden are somewhat expanded 
near cell wall. ¢, austoria of Kny. Expanded knobbed extension from the 
strands. ue 
Fig. 3. Rootlet of Melilotus alba. a, Developing tubercles. 4, Single tubercles. 
c, Grape-like bunches of tubercles, slightly magnified. 
Fig. 4. Rootlet of Amphicarpza comosa with spherical tubercles. 
Fig. 5. Rootlet of Dalea alopecuroides. Tubercles resembling those of A/edi/otus alba 
and Trifolium pratense and 7. repens though somewhat larger. 
Fig. 6. Portion of infected arc of 7rifolium repens showing nuclei treated with KHO 
solution, and cell protoplasm (mycoplasm), «a, Nucleus enlarged. 4, Cell 
protoplasm (mycoplasm). partially used by the plant containing modified 4’ hizo- 
bium mutabile, c, Infektionsfiden. They seem to be entirely independent of 
cell nuclei and mycoplasm. d, Haustoria of Kny. They do not appear granu- 
lar while the strands do. 
PLATE CXXX. 
Fig. 1. Rhizobium mutadile as it appears in May, or the time of infection. 
Fig. 2, The same in June and July. 
Fig. 3. The same in September and October. a, A Rhizobium from which the plant 
has begun to reabsorb the contents. 
Fig. 4. The same in October and November. a, Partially emptied A/izobia. b, En- 
tirely empty, nothing remaining but the partially destroyed walls. ¢, Normal 
forms which either had not undergone any change in the cell or had just 84 inet 
access to the tubercle through its partially decayed distal end. . 
Fig. 5. Rhizobium curvum. 
Fig 6. Rhizobium Frankii, var. majus, 
_Fig. 7. Rhizobium Frankii, var. minus, 
Fig. 8. Rhizobium nodosum, 
Fig. 9. Rhizobium dubium. 
