Fe er Fee oe a eee ee ee ee re eet oe ee 
1893. ] The Organism of Leguminous Tubercles. 257 
Contribution to the biology of the organism causing 
leguminous tubercles. 
GEO. F. ATKINSON. 
WITH PLATES XII-XVv. 
(Concluded from p. 237.) 
Comparative review. 
This brings the history of the more important contributions 
to the biology of the leguminous tubercle organism, that have 
come to the notice of the present writer, down to the present 
time. The record presents a discouraging volume of conflict- 
em which deny any external agent of a microbic nature will 
always remain important expositions of the structure and de- 
velopment of the tubercles. Had more attention been given 
by neve investigators to careful cultural experiments perhaps 
they might have come to different conclusions. The charge 
Si perhaps be made that cultural experiments are un- 
in Met since Tschirch®? and Frank®® assert that steriliz- 
tas © soil by heat so changes its physical condition as to in- 
ea rate development of the tubercles. Frank*® and 
also believe that the formation of the tubercles 
ess of th. 
SToundless, The 
present Writer sho 
Vigor in the plant 
tCles if the p 
nh yi 
ew of all the cultural experiments referred to above, 
o7 
reac entrall, XXX1 (1887). 
aettwickel + Einfluss, welchen das Sterilisieren des Erdbodens auf die Pflan- 
"Untersuche tusubt. Ber. d. deutsch. bot. Gesells. vr (1888). XCV. 
‘cb. vr (aggen Uber die Ernahrung der Pflanze mit Stickstof. Landw. 
“*Jour, fir 7 yt. 
Wirtschaft, xxxrr (1885). 330. 
