PHYSIOLOGY: MURPHY AND MORTON 
435 
lint 
n= -\- CO 
lim 
f(x)<p{n,x-a)dx = if(a + 0) 
'a 
f (x) (p {n,x — a) dx = if (a — 0) 
Theorem IV is a corollary of Theorem III. 
While the forms of representation for an arbitrary function / (x) 
afforded by the preceding theorems do not, strictly speaking, represent 
the function in terms of definite integrals, but rather in terms of the 
limits of such integrals as the parameter n increases to + , it is to be 
observed that the first member of (2) may always be expressed as a con- 
vergent series, viz : 
and thus it appears that to every integral (2) obtained by any one of the 
preceding theorems there corresponds an actual representation of the 
arbitrary function in series of definite integrals. 
THE LYMPHOCYTE AS A FACTOR IN NATURAL AND IN- 
DUCED RESISTANCE TO TRANSPLANTED CANCER 
Histologically there is a striking resemblance between the series of 
phenomena which take place about a failing tissue graft in a host of a 
foreign species, and an homologous cancer graft in an animal with a 
natural or induced immunity to transplanted cancer. A constant find- 
ing in both cases is a local lymphoid reaction which appears early in 
the process, and lasts till the destruction of the tissue or cancer graft is 
complete. We have shown in previous communications that the lym- 
phoid tissue is apparently the important factor in the destruction of a 
tissue graft in an animal of a foreign species. The facts which lead up 
to this conclusion are, that an organism like the chick embryo, which 
normally has no defensive agents against the cells of a foreign species, 
if supplied with adult lymphoid tissue becomes as resistant as the adult 
animal in this respect. Furthermore when the adult animal is deprived 
of the major portion of its lymphoid tissue by repeated small doses of 
X-ray, it loses the ability to destroy the cells of a foreign species and 
these will live and grow as well as they would in a native host. It 
By James B. Murphy and John J. Morton 
ROCKEFELLER INSTITUTE FOR MEDICAL RESEARCH. NEW YORK 
Presented to the Academy. June 22, 1 9 1 5 
