282 AN ELEMENTARY TEXT-BOOK OF BIOLOGY. 



from its hinder part towards the mid-ventral line, and unites 

 there with its fellow to form the posterior portion of the ischio- 

 pubic symphysis. 



The cotyloid is a very small bone helping to form the ventral 

 side of the acetabulum, from which it shuts out the pubis. 



The small pubis runs from the cotyloid bone towards the 

 mid-ventral line, and unites with its fellow to form the anterior 

 part of the ischio-pubic symphysis. 



Free Limb. The elongated femur presents a proximal head 

 upon its inner (preaxial) side, which articulates with the aceta- 

 bulum, and two distal condyles which articulate with the tibia to 

 form the knee-joint. The actual proximal end of the femur is a 

 large projection known as the great trochanter. There is* a lesser 

 trochanter below the head, and opposite this on the outer (post- 

 axial) side a third trochanter. 



A large patella is present on the front of the knee-joint, at 

 the back of which are two other sesamoid bones, the fabellae. 



The cms is supported by the large preaxial tibia, which pos- 

 sesses two proximal concavities for the femur, and two distal 

 surfaces for the tarsus. With the tibia a small, postaxial, rod- 

 like fibula, is completely fused distally. 



The ankle-joint in the rabbit is between the distal ends of the 

 above bones and the tarsus. 



The tarsus is made up of proximal and distal rows partly 

 separated by a large centrale (navicular). 



The proximal row contains two bones, the preaxial (a) tibialo- 

 intermedium (astragalus), and postaxial (/3) fibulare (calcaneum) 

 produced into a large projecting heel. The distal row is com- 

 posed of three bones, which are, beginning preaxially, (a) tarsale 2 

 (mesocuneiform), (j3) tarsale 3 (ectocuneiform), and (y) tarsale 

 4 -f tarsale 5 (cuboid). 



There are four digits, the first or hallux being absent. Each 

 possesses a metatarsal, the first of which is produced proximally 

 into a process, originally separate, which may represent the miss- 

 ing hallux. Each digit is completed by three phalanges, similar 

 to those of the manus. 



Small nodular sesamoid bones are developed in the tendons, opposite the 

 joints on the under (ventral) side of manus and pes. 



4. The digestive organs (Fig. 85) consist of an alimentary 



