FEBRUARY 2, 1912] 
is quite parallel to that which occurs in 
certain cancers of secondary origin where 
the structure of the primary tumor is out- 
lined, albeit often only imperfectly. We 
might now inquire whether primary tumors 
produced on leaves do not have the same 
structure as those just described as secon- 
dary tumors. We have made needle-punc- 
ture inoculations on leaves of Paris daisy 
and have studied the structure of the 
tumors which develop and these do not 
have a stem structure but an irregular epi- 
thelioma-like structure derived wholly 
from the leaf, as may be seen from the 
lantern slide exhibited. 
What happens finally in the case of 
cancer happens in crown-gall, namely, the 
tissues not being sufficiently vascularized, 
and composed of a great excess of soft and 
fleshy cells, are easily disorganized with the 
production of open wounds. In case of 
erown-galls on the daisy and many other 
fleshy plants after about two or three 
months large portions of the tumorous 
tissue decay with the formation of open 
wounds, subject to a variety of secondary 
infections. 
It should be stated here, however, that 
in the crown-gall there are no abscess ecavi- 
ties such as we find often in granulomata 
or in such a disease as olive tuberculosis. 
Sometimes there is a multiplication of bac- 
teria in the vessels in the vicinity of the 
needle puncture, but whether these are 
the crown-gall organisms or not we have 
not yet determined. 
when the tumor has begun to grow rapidly 
no bacteria or other granular matters have 
been found in the vessels or in the inter- 
cellular spaces. The causal bacteria occur 
- inside the cells, which are stimulated by 
their presence to multiply with great rapid- 
“ity and without reference to the physiolog- 
ical needs of the plants, 7. e., the plant has 
no direct control over the growth. 
SCIENCE 
Certain it is that: 
167 
In these particulars crown-gall resembles 
epitheliomatous growths, while in the em- 
bryonal character of its luxuriant granu- 
lations and in its predilection for young 
plants and rapidly growing tissues it is 
more like sarcoma. The growth is a hyper- 
plasia rather than a hypertrophy, although 
occasional groups of large cells occur. 
There can be no doubt as to the develop- 
ment of new vessels in the growing tumor. 
This is shown clearly by the anatomy of 
the secondary tumors. Whether the ves- 
sels are ingrowths from the surrounding 
tissues, or outgrowths from the tumor 
strand, or both, as would seem to be the 
case, must be left for further inquiry. The 
anatomy is unlike that of club-root of cab- 
bage, where the growth consists of an 
enormous enlargement of a comparatively 
few infected cells. 
I think, therefore, that we have in crown- 
galls a striking analogy to what occurs in 
malignant animal tumors, namely, to re- 
capitulate, the cell itself a disturbing force, 
i. €., an enormous multiplication of certain 
cells of the body without reference to phys- 
iological needs and in opposition to the 
best interests of the organism; a non-cap- 
sulate tumor, with absence of abscess cavi- 
ties and of plainly visible parasites; per- 
ipheral growth and a_ well-developed 
stroma consisting of vessels and fibers; 
from this primary tumor the development 
of strands of tumor tissue upon which see- 
ondary tumors develop; in the secondary 
tumors a strong tendency to take on the 
structure of the organ in which the pri- 
mary tumor has developed; frequent if not 
necessary origin of the primary ‘tumor in 
bruises, wounds or irritated places; com- 
plete recovery if all the tumor tissue is 
extirpated, failure if it is not; in some 
cases spontaneous recovery. The chief dif- 
ference so far made out is that in case of 
eancer cells we know nothing whatever as 
