238 
AMERICAN JOURNAL OF BOTANY 
[Vol. io. 
lenses. This immune serum injected into rabbits produced no direct 
reaction; but defects of the crystalline lens appeared in the progeny of both 
male and female through several generations according to a definite ratio. 
The immune body for anatomical reasons may not come in contact 
with the crystalline lens, so that we appear to have two alternatives. Either 
the immune body is transmitted, enters the germ as a new factor, and 
appears in the developing embryo with destructive effects upon the lens; 
or, in the injected animal the immune body combines with the lens deter¬ 
miner in the germ plasm and effects its destruction or alteration. If this 
be true, according to the fundamental basis of immunology, the immune 
body combines with the determiner because of chemical identity between 
the substance of the determiner and that of the immune body antigen, 
i.e ., the lens. In other words, the development of lens is conditioned by 
the transmission of chemically similar substance in the germ. 
It is t most significant that, in so far as chemical specificity has been 
-determined, it is in close agreement with relationship based upon structural 
features. We may be permitted to conclude, therefore, that the constitu¬ 
tion of the protoplasm is the fundamental species characteristic, of which 
form and structure are manifestations. This perhaps strengthens the 
frequent claim that physiology regards species too lightly, yet at the same 
time it provides a rational basis for physiological generalization and physio¬ 
logical specialization. We may generalize when we have to do with non¬ 
specific reactions of protoplasm or with agencies which influence in a similar 
manner the various specific constituents; we must specialize when we have 
to do with the specific substances of the protoplasm. 
Queen’s University, 
Kingston, Canada 
