FEBRUARY 16, 1912] 
more specific, he will find that in his phrase 
“Tf ...I1 am a redevelopment of the char- 
acteristics of some former individual from 
a piece of his body,” the words “I” and 
the group of words “characteristic of some 
former individual” exactly cancel each other 
and leave an intellectual blank, just as do 
the words “cubical” and “spherical” when 
the attempt is made to apply them to one 
and the same body. That is to say, despite 
the splendid combination of breadth of 
outlook and ability as a laboratory method- 
ologist and technicist which distinguishes 
Jennings as a biologist, his address at this 
point is subject to the same miscarriage of 
reason that has characterized nearly all mod- 
ern speculative thinking on the Mendelian 
type of inheritance. The miscarriage to 
which I refer arises from neglecting the tech- 
nical detail of noticing that since there al- 
ways is a strictly psychological or subjective 
element in the idea expressed by the term 
“ characteristic,” it comes about that the very 
construction of the sense-perceptional aspect 
of our knowledge is such as to make it utterly 
impossible for the truly same characteristic 
to belong to more than one body. This funda- 
mental truth has been overlooked in specula- 
tive biology largely, I suspect, from failure to 
note that so far as the subjective side of per- 
ception is concerned, “characteristic” is ex- 
actly synonymous with “ quality ” and “ prop- 
erty.” Bearing this fact in mind, the situa- 
tion clears up readily when we turn to the 
familiar practical (not, generally, the theo- 
retical) language of chemistry. The working 
chemist never for an instant thinks of trying 
to express or “ explain ” the characteristics, or 
properties of hydrogen in “terms of” the 
characteristics of oxygen, for he knows per- 
fectly well that were he able to do such a thing 
there would be no such gas as hydrogen, for 
all hydrogen would be oxygen. There is no 
doubt in the world, as one sees if he looks at 
the case closely, that most of the recent ef- 
fort to “explain” the adult organism in 
terms of the germ cells has involved just the 
self-destructive fallacy that the chemist would 
be a victim of were he to try to explain 
SCIENCE 
269 
hydrogen in terms of oxygen. The fact that 
the adult organism develops from the germ 
cells while oxygen does not, so far as we 
know, develop from hydrogen, does not in the 
least affect the psychological fact that the 
adult is known by its own characteristics and 
in no other way, exactly as the germ cell is 
known by its characteristics and in no other 
way. 
Once one sees clearly that this aspect of the 
problem of genetics differs toto celo from the 
problem of developmental potentiality, that is, 
the problem of how the germ cell is able to de- 
velop into the adult, he has gone a very long 
way toward a consistent, workable philosophy 
of biology. 
In Jennings’s sentence “if the phrase ‘ po- 
tential immortality’ means anything for the 
infusorian, it means exactly the same for me, 
so far as we can judge from past history,” I 
find encouragement for the hope that he will 
be willing to give my principle of standardiza- 
tion a good testing. 
“e 
Wm. E. Rirrer 
MARINE BIOLOGICAL STATION OF SAN DIEGO, 
La JOLLA, CALIFORNIA, 
January 4, 1912 
THE CHESTNUT TREE DISEASE 
To THE Epitor oF Scmence: In connection 
with the chestnut tree disease mentioned in 
Science of December 29, 1911, and in preced- 
ing numbers, the writer calls attention to the 
hardy giant chinquapin (Castanopsis Chry- 
sophilla) of the Pacific states. This may be 
a resistant species adaptable to the southern 
states. It occurs in two varieties, the one 
just mentioned and a dwarfed variety. The 
former reaches a height of 120 feet and has a 
diameter of from 8 to 10 feet; ordinarily 
from 40 to 55 feet in height and from 1 to 2 
feet in diameter. Locality, near Willets in 
Mendocino County, Cal. The dwarfed form 
is abundant in the Cascade and Sierra Ne- 
vada and San Jacinto mountains from 2,000 
to 9,000 feet. It is mostly of shrubby habit, 
but to all appearances identical with the 
giant chinquapin. This latter is a hardy and 
long-lived evergreen of stately and handsome 
