194 
JOURNAL OF mammalogy 
THE OCCURRENCE OF A STERNAL GLAND IN ORANG-UTAN 
By Adolph H, Schultz 
[Plate 14 ] 
During the examination of a fetal male orang-utan (crown-rump 
length 145 mm.)/ in which the lanugo was still for the most part 
microscopic, the author’s attention was attracted to a small circular 
pit in the middle of the smooth sldn of the chest. This pit was easily 
visible and a closer study proved beyond doubt that it was not due to 
injury, but was evidently a natural opening in the skin. An older 
male orang-utan fetus, near term (crown-rump length 230 mm.) 
showed the same pit at a corresponding place on the chest (see figure 1). 
From this specimen an area of skin, including the pit, was removed 
and sectioned. The histological examination of the sections cleared 
up the nature of this structure. It was found to be the opening for a 
considerable number of large sebaceous glands conglobated beneath. 
The pit is situated in the midsagittal plane, shghtly above a line 
connecting the nipples, and overlies the manubrium sterni. Based 
upon their location the gland may be termed sternal gland and its 
opening sternal pit. 
The examination of a total of twenty-three specimens of orang- 
utan ranging in age from fetuses to very old specimens and including 
both sexes, revealed some interesting facts regarding the occurrence of this 
sternal gland. The author wishes to express his sincere thanks to 
Mr. G. S. Miller for his kind permission to study five preserved orang- 
utan fetuses and newborns and a number of adult skins in the National 
Museum; to Mr. N. Hollister for the opportunity to examine the 
orang at the National Zoological Park; to Mr. R. L. Ditmars for 
information regarding the orang at the New York Zoological Park; 
and to Dr. E. Huber for his careful notes on some preserved orangs 
of the University in Zurich. 
The gland was found to be present in 12 out of 13 males and in 2 out 
of 10 females. The only male in which it was missing was a very old 
specimen, and this, together with the fact that in the fairly old orangs 
the pit was relatively much smaller than in the juveniles, would indicate 
that the gland degenerates gradually with advancing age. The only 
two females in which the pit was present were juveniles, the fetal, 
1 No. 143597 U. S. Nat. Mus. 
2 No. 153973 U. S. Nat. Mus. 
