236 
NOCARD AND ROUX. 
with traces of the opal fluid thus obtained, the other with the 
same culture, which has been previously heated; with this last 
ba^ the culture will remain identical with the witness bag 
above mentioned ; its contents will remain clear and transpar¬ 
ent, while the other one will be opalescent and cloudy, with the 
numerous refringent points already described; heat had killed 
the germs of the first one. 
With the opal liquid of the fertile bag of the second rabbit, 
other bags can be inoculated and be placed in the peritoneum 
of a third rabbit and so on, and always identical results will be 
obtained. It is wise, however, to use several bags in each pass¬ 
age, as the rupture of a bag is quite common.* 
Most ordinarily rabbits have lost much flesh when they are 
to be killed ; sometimes they even die before the day fixed for 
the autopsy : they are then in a deep state of cachexia, only 
skin and bones ; post-mortem, however, reveals no noticeable 
organic lesion ; the blood and pulp of the parenchymas, inocu¬ 
lated in various media, even in collodion bags, give no culture; 
then it is, according to all probabilities, an intoxication due to 
the diffusion, outside of the bag, of the products elaborated by 
the microbe; at any rate they cannot be attributed to digestive 
troubles (or others) which would be due to the presence of the 
bag (foreign body); when the bouillon has not been inocu¬ 
lated rabbits may receive several bags and keep them for 
months, without showing the least disturbance, without losing 
one gramme of their weight. It has seemed to us that these 
accidents were so much more marked and cachexia deeper that 
the bags, introduced after inoculation were more numerous, of 
larger dimension or that the culture obtained was richer. 
Here, then, is a new example of an animal becoming very sen¬ 
sitive to the toxines of a microbe against which, however, he is 
refractory. 
We have tried several times to obtain cultures in bags with 
* The bag of collodion can be advantageously replaced by one made with the fine tu¬ 
bular membrane of reed-cane, which according to Metchnikoff offers also an obstacle to 
the microbes and to the cells, still being permeable to liquids and substances in solution. 
It is also very strong and resisting. 
