BULLETIN 
OF THE 
TORREY BOTANICAL CLUB. 
Vol. XIX.) New York, July 18, 1892. [No. 7. 
Observations on some American Rhizobia. 
By A. SCHNEIDER, University of Minnesota. 
Plates CX XIX and CXXX. 
The purpose of. this paper is: first, to give a short review of 
“Pilzsymbiosis;” second to point out and discuss somewhat the 
existing controversies; and third, to show that there are probably 
more than one species of Rhizobium. 
It is only within recent years that the symbiotic relations of 
fungi with plants have been discovered and studied. Half a 
century ago some of the fungi which are now known to be 
Symbiotic were studied and described without suspecting their 
real nature. Theo. Hartig in 1840 made drawings and gave a 
- description of the “‘mykorhiza” of Pinus sylvestris, taking it to be 
4 purely parasitic fungus. With this in view, at the “ Botanischer © 
‘Verein in Miinchen,” Nov. 11, 1885, R. Hartig criticises Frank 
for claiming to have discovered the symbiotic relations of Kose/- 
linta quercina with the oak To my knowledge nothing of any 
moment had been done on Pilzsymbiosis prior to 1885. _B. Frank 
no doubt is the most earnest worker and has done more than any 
other man to clear up some of the mysteries concerning the sub- 
= ject. Probably he often becomes too enthusiastic over his discov- 
€ries, claiming for instances that many trees, especially of the 
 Cupuliferee, cannot develop without the symbiotic fungi. R. 
Hartig seems to be of the opposite turn of mind. In his “ Anat- 
omic und Physiologie der Pflanzen,” 1891, he sums up Pilzsym- 
biosis as follows: “ Fungi probably belonging to the Tuberaces or 
Gastromycetea: are found parasitic on, or symbiotic with certain 
