1064 The American Naturalist. [December, 
great interest as indicating what may be expected from 
a further study of this subject. 
In this case, he experimented with ricin and abrin, those 
toxic vegetable alkaloids that are so closely related to the poi- 
sonous products of bacterial growth. The question at issuein 
his experiment was, whether the male or the female cell, if 
‘either, possessed the ability to transmit artificial immunity to 
its progeny. His methods were, to first pair a highly immun- 
ized male rabbit with a normal susceptible female, and deter- 
mine whether the progeny possessed any immunity against 
the toxic substance. In this series of experiments, he found 
that the descendants invariably succumbed when inoculated 
with the ordinary fatal dose. From this it is evident, he says, 
* that the idioplasm of the sperm is not in condition to trans- 
mit acquired immunity. ”? He then took up the more com- 
plex problem of the inheritance of maternal immunity. The 
problem in this case is more diffieult because we cannot tell 
with certainty whether the immunizing substance passes to 
the foetus by the way of the germ plasm, or directly through 
the foetal membranes. This difficulty is partially obviated if 
the immunity is conferred before fertilization of the egg 
oecurs. But here another disturbing factor arises and that is 
to confer a permanent immunity for extended periods of time. 
Repeated tests with these alkaloids demonstrated the permancy 
of the immunity as very marked in this case, so that they 
were well suited for experiment on this question. He institu- 
ted another series of experiments on rabbits, by pairing an 
immunized mother with a male of normal susceptibility. 
Here he found a well pronounced immunity conferred upon 
the progeny for a certain length of time. At the age of three 
or four weeks, the young were able to stand ten times the dose 
that was ordinarily fatal, but in a month and a half it had 
almost entirely disappeared, and in three months the animal 
yielded readily to the injection of the normal lethal dose. No 
?Since this was written, Tizzoni and Centanni have published (Cent. für Bakteriol- 
ever not uniform but they are of interest in this connectiom as showing how import- 
t je an experi tal standpoint ; į 
