232 BOTANICAL GAZETTE [MARCH 
ten generations on media containing 5 or 6 per cent. of salt. Conidia from each 
of these strains were Sown in solutions containing 20.4 to 22 per cent. of salt. It 
was found that conidia from strains which had previously been accustomed to 
6 per cent. salt solution germinated more rapidly and grew more vigorously than 
conidia from normal solutions. Conidia from the strain accustomed for ten 
generations to salt showed the same effect in a more pronounced manner. When 
conidia from all strains were sown on normal nutrient solution, the strains adapted 
to salt grew more poorly and consequently fruited sooner than the strains not 
adapted. When all strains were sown on salt solution, the reverse effect was 
rved. The accommodation to salt solution did not disappear after ten genera- 
tions of culture on normal media. Attempts to establish persistency of accommo- 
dation to higher osmotic pressures and to some poisons gave negative results. 
The author has attacked this problem, as he states in the introduction, from 
the standpoint of inheritance of acquired characters. It seems doubtful if the 
idea of inheritance can be applied perfectly in such cases as described in the fore- 
going, where the whole protoplasm in the organism is modified by a factor in the 
environment, and a part of this modified protoplasm passes into the conidium— 
an asexually formed bud of the original stem. So.long as no sexual process inter- 
venes, the succeeding ‘‘generations” must be looked upon as a continuation of 
the original plant. Therefore, organisms with only asexual reproduction are 
not well suited to the study of the inheritance of acquired characters. That some 
of the characteristics should not be lost readily, i. e., that the organism should not 
readapt itself readily to the former condition, may appear unusual, but it is pos- 
sible that the reactions by virtue of which th ti t readily 
reversible. If this principle were general, it would lead to the existence of numer 
ous physiological races. Such races are common among parasitic fungi, and it 
may be that they are even more numerous and as highly specialized among the 
saprophytes.—H. HAssELBRING. 
Tubercle bacteria.—Dr’Rosst working at Perugia has been investigating 
anew the Bacillus radicicola of BEIJERINCK, and has reached results so at variance 
with those of previous observers as to need ample confirmation.'s His conclusions 
may be stated briefly as follows: 
An examination of the literature convinces him that many observers have 
mistaken germi banali of the soils for the real B. radicicola; and others have worked 
with impure cultures of it. The certain isolation of the true germ is attained by 
spreading the contents of a tubercle on a plate of gelatin with a leguminous extract 
containing glucose, and rejecting the colonies which develop rapidly, in favor of 
those which become visible to the microscope on the fifth or sixth day and to the 
eye on the tenth to twelfth, the form really desired being apparently a contaminant. 
These show the true morphological, cultural, and biological characters of 
B. radicicola. 
j 
13 DE’Rosst, G., Studi sul microorganismo produttore dei tubercoli delle legumi- 
nose. Annali di Botanica 7:617-669. pl. 23. 19 
