436 ANIMAL PHYSIOLOGY. 
secondary importance. We doubt, however, if the results of 
the above-mentioned experiment warrants any inferences as to 
the normal glycogenic functions. , 
The instructive part about the disease diabetes is the man- 
ner in which the course of events emphasize the importance 
of co-ordination among the vital processes, and the constant 
necessity for regulation of them all by the nervous system. 
Diabetes seems to imply that these processes have escaped this 
normal control and are running riot. 
METABOLISM OF THE SPLEEN. 
The physiological significance of the peculiar structure of 
this organ, though not yet fully understood, is much plainer 
Fia. 330.—Vertical section of a small superficial portion of human spleen, seen with low power 
(Schafer). A, peritoneal and fibrous covering ; b, trabecule ; c, c, Malpighian corpuscles, 
in one of which an artery is seen cut transversely, in the other, longitudinally ; d, injected 
arterial twigs ; e, spleen-pulp. 
than it was till recently. The student is recommended to look 
carefully into the histology of the spleen, especially the dis- 
tribution of its muscular tissue and the peculiarities of its 
blood-vascular system. It has already been pointed out that 
there is little doubt that leucocytes are manufactured here even 
in the adult, possibly also red cells; and that the latter are dis- 
integrated, and the resulting substances worked over, possibly 
by this organ itself. This view is rendered probable, not only 
by microscopic study of the organ, but by a chemical examina- 
