SUPRARENAL GLAND—EFFECTS OF INANITION 241 
it is further considered that the majority of the middle-zone 
mitoses occur in the outer part of the zone, it is evident that 
in general the outer portion of the cortex is the chief cortical 
germinative region. Some mitoses are found scattered through- 
out the cortex, however, an occasional one being found even in the 
inner zone (reticularis). In general, mitoses disappear first 
in the medulla, and the inner cortical zone, and later in the 
middle zone, persisting longest in the outer cortical zone. 
The occurrence of amitosis in the suprarenal has been: {aimed 
by various investigators. Mulon (03 b, ’05a) in particular 
even maintains that in the guinea-pig amitosis is the predom- 
inant type of cell division in the suprarenal, mitosis being much 
less frequent. Kolmer (12 b), on the contrary, found mitoses 
more frequent (occasional amitosis) in the suprarenal cortex 
of the younger guinea-pigs, though in older, non-pregnant fe- 
males amitosis was observed with no mitosis. Most authors 
have considered amitosis in the suprarenal (as elsewhere) to 
be atypical and degenerative in character. Thus Poll (’99) 
observed amitosis (more rarely mitosis) in the degenerating 
cortical cells in transplanted suprarenal glands of the rat. Del- 
amare (’03) observed occasional amitosis in the senile human 
suprarenal cortex, producing multinucleated masses. Bonna- 
mour (’05 a) believes that the figures which have been inter- 
preted as amitosis (direct division), especially in the outer cor- 
tical zone and in the medulla, are merely deformed nuclei, without 
significance for cell division. 
In relation to age, cell division (especially mitosis) in the 
suprarenal has generally been found more frequent in young 
animals, as might be expected, and especially in fetal stages 
(Canalis). It has also been observed in adults, especially in 
the outer cortical region, by Canalis (’87) in the dog, guinea- 
pig, rabbit, and mule, Mulon (’03 b) (guinea-pig), Kolmer (’12 b) 
(guinea-pig), and others. Da Costa(’13) has observed mitoses 
in the cortex of both young and adult dog and guinea-pig. 
It is interesting to note that the rate of mitosis in the young 
rat corresponds rather closely to the growth of the gland in 
absolute and relative weight. As previously shown (Jackson, 
