No. 377.] REVIEWS OF RECENT LITERATURE. 367 
with sterile earth and watered with sterile water, the part below being 
put into ordinary earth mixed with bruised tubercles. The whole 
was then protected from air infection by a glass cover. Root tuber- 
cles formed on this lower part of the root, but none were found on 
the root and rootlets grown in the sterile earth. Cultures from the 
part of the roots grown in the sterile earth and from the parts above 
ground yielded negative results; bruised portions added to sterile 
soil also failed to cause any root tubercles on the roots of seedlings 
grown therein. The reverse experiment was tried, z.¢., using infected 
soil in the upper chamber and sterile soil below. In this case tuber- 
cles formed on the roots in the upper chamber and not on those in 
the lower one. Cultures and soil infections from these lower roots 
yielded negative results. These experiments indicate that the germs 
cannot migrate from the tubercles to other parts of the plants. 
3. Mr. Zinsser determined with considerable care the length of 
time the root tubercle organisms of Phaseolus multiflorus are able to 
live when injected into germinating seeds, young roots, young and 
old stems, leafstalks, etc., of various legumes. His conclusions do 
not differ much from results obtained by numerous observers work- 
ing with all sorts of organisms non-pathogenic to plants. In other 
words, they were able to retain vitality and make a feeble growth for 
a variable period, usually two to ten weeks, but only in close prox- 
imity to the place of insertion, the germs being injected by means of 
a Pravaz syringe. The infectious material was derived from pure 
cultures and also directly from the tubercles. 
4. Water washings from the root tubercles of three different 
legumes (P. multiflorus, V. faba, and Z. albus) were injected into a 
great variety of plants (forty-two species of many different orders), 
but after eight weeks the organisms were not to be found in any of 
them either at the point of insertion or two centimeters away. 
Moreover, on the roots of none of these plants could tubercles be 
induced, although abundant washings of root tubercles were added 
to the earth. -Pure cultures and tubercle washings from Phaseolus 
multiflorus, P. vulgaris, Vicia faba, Lupinus albus, and Pisum sativum 
were also injected into the callus on cut branches of locust, 
poplar, and willow, but after forty days no living bacteria were to 
be found therein. 
5. The author also tried the behavior in plant tissues of a variety 
of micro-organisms non-pathogenic to plants, with results much like 
the preceding and entirely confirmatory of what we already know, 
namely, that many saprophytes and animal parasites are able to live 
