258 Cc. M. JACKSON 
opacity caused by them. The extracapsular fat droplets, on the 
other hand, appear clear and light. The liposomes present the 
same reactions mentioned for the new-born. 
The amount and distribution of the liposomes are most élearly 
shown in the frozen sections stained with scarlet red (fig. 4). In 
the narrow outer zone, they are usually very abundant and closely 
packed, the largest droplets somewhat exceeding the average 
nuclear size. The subjacent clear line or narrow band is rela- 
tively (but not absolutely) free from liposomes. They are most 
abundant and closely packed in the outer half of the middle zone, 
where the largest may reach double the average nuclear diameter. 
In the inner half of the middle zone they become more or less 
reduced in amount, and are usually scanty in the inner cortical 
zone (aside from those associated with the pigment cells). No 
liposomes are present in the medulla, aside from occasional groups 
which appear in the cortical islands near the boundary. 
. The distribution of liposomes in sections stained with osmic 
acid corresponds closely with that in sections stained with scarlet 
red. Thestriking contrast in the staining reactions of the cortical 
lipoids and the extracapsular ordinary fat was mentioned in the 
new-born suprarenal, and is constant. The pigment cells (lipo- 
chrome) of the inner cortical zone frequently react more like the 
ordinary fat, however, staining a lighter reddish than the lipo- 
somes with the scarlet red and darker than the liposomes in prep- 
arations stained with osmic acid. 
The amount and distribution of lipoids, as is well known, vary 
much according to age and species. In general, the formation of 
lipoids begins during the prenatal period (Poll, ’05; Starkel and 
Weegrzynowski, 710), and increases during postnatal life, though a 
decrease in the human suprarenal fat after childhood is noted by 
Napp (’05). As to species the lipoidal content appears greatest 
in man, carnivora, and rodents, less in ruminants and pachy- 
derms (Ciaccio, ’10, and others). The lipoids are usually, as in 
the rat, most abundant in the middle zone, with less in the outer 
and inner zones. In some cases, however, a greater abundance 
of lipoids of the outer zone has been observed (Hultgren and An- 
derson, 99; Ewald ’02; Napp, ’05; Bonnamour, ’05 b; Starkel and 
