24 ELEMENTS OF MAMMALIAN ANATOMY. 
A tubercle is a small and usually more 
or less pointed process. 
A condyle is a rounded and somewhat 
elongated smooth articular process. The 
distal end of the femur presents a pair 
of condyles (Fig. 40). 
A fossa is an irregular depressed area 
(Fig. 30). 
A foramen is an aperture for the pas- 
va + sage of vessels or nerves. 
ee The shaft is the body or middle por- 
ud tion of an elongated bone. 
The head is a spheroidal prominence 
[ at one end of an elongated bone (Fig. 
40). 
The epiphysis is a small process of 
bone ossified from a separate center. In 
the young animal it is attached to the 
main bone by cartilage, but in the adult 
becomes a part of the main bone (Fig. 
12). The femur has four epiphyses, 
one for the head, one for the distal ex- 
tremity,and one. for each trochanter proc- 
ess (Fig. 40). With the exception of 
soot Eee the phalanges, metacarpals, and metatar- 
or THE Femur sals, all of the long bones have an epi- 
eels physis at each extremity. In the human, 
cancellous tis- these epiphyses do not unite with the 
sue; #7, cancel, shaft before the sixteenth year. Diploé 
lous tissue of 
trochanter proc- is the spongy layer of bone between the 
ess; b, compact i 
bony tissue. compact surface layers of the flat bones 
(Fig. 18). 
The articulation of a bone has reference to its contact 
with other bones by means of joints. 
