127 
ic acid, then with pure water. To this was added a solution of 
nourishing material of a certain known composition, afterward the 
pots holding this prepared soil were placed in a steam sterilizer 
and heated for several hours. A slight quantity of soil, taken 
from the earth where Rodinia trees grew under ordinary condi- 
tions, was then placed in each pot. This was to supply the 
young plants with germs of the supposed bacteria. Seeds were 
then sown, a single one in each pot, and the resulting plants kept 
in the hot-house and watered with distilled water. After the 
growth of a single summer the plants were examined and sub- 
jected to chemical analysis. All had developed the little tubers 
supposed to be caused by bacteria, and there were found in dif- 
ferent conditions, some entirely emptied of contents, others yet 
tense, and hard with all intermediate stages. The chemicai 
analysis showed the quantity of nitrogen contained in the plants 
to be something more than thirty-eight times that contained in 
the seeds. This nitrogen could have been obtained from no 
other source, it is claimed, than the free nitrogen of the air. In 
order to show more clearly the function of the tubers and their 
connection with the bacteria germs, a few pots were prepared 
without the earth from outside, but allowed to stand in the same 
room with the others. These plants also developed tubers, 
though less in number and less well developed, which Dr. Frank 
says could have come from no other source than the germs es- 
caped from the other pots. Various precautions were taken to 
avoid this infection, such as covering the surface with cotton, etc., 
but the simpler method of removing the pots from the atmosphere 
surrounding the infected plants seem not to have been tried. 
BA. G, 
Recherches sur la Vrille des Passiflores, par M. W. Russell. 
( Bull. Soc. Bot. de France, xxxvii. 189-192). 
The rameal nature of the tendrils of the Passiflore is well 
known, but their origin is a source of considerable discussion 
among botanists. According to various authors there exists in 
the axils of the leaves two or three organs, of which one repre- 
sents the axillary branch, whereas the others are either accessory 
ramifications, or normal ramifications of the same or of a differ- 
ent order. 
