Hertwig 235 
munity against ricin, just so according to Hertwig’s view 
do all the cells behave toward acquired characters in gen- 
eral. “In the same way as the cell is sensitive to the 
action of ricin, which brings about an enduring material 
modification of it, and this becomes inherited as im- 
munity to ricin, so I think every cell is sensitive also to 
the influence of the general condition of the body, which 
brings about material modifications of its substance, that 
is of its idioplasm or hereditary material, which is es- 
pecially susceptible of such material modifications, and 
these correspond to the cause as its effect both in the cells 
of the soma and also in the sexual products.” 18? 
We shall not consider here the fact demonstrated by 
Ehrlich, that in the instance in which only one of the 
parents was immunized, the immunity was transmitted 
very well to the young of an immunized mother but on 
the contrary was not transmitted to the young of an im- 
munized father; a fact which seems to confirm the 
hypothesis of Ehrlich that the immunity against ricin was 
due to the formation of an anti-ricin, with which the 
protoplasm of all the cells became impregnated, but with 
which the spermatazoon could not become impregnated 
because it is almost entirely devoid of protoplasm, show- 
ing consequently that one has to do here not at all with a 
permanent modification of the nuclear idioplasm. But 
even apart from that and even admitting the hypothesis 
that the immunity against ricin was due from the be- 
ginning or at the time to the acquisition by the idioplasm 
of a new and persistent character,’*® it is still evident 
that this is not a just comparison. 
For in the case of infections, immunizations, and so 
181Oscar Hertwig: Ibid. II. P. 242. 
182Qscar Hertwig: Ibid. P. 241. 
