BY C. J. MARTIN- AND FKAXK TIDSWELL. 483 



side are the muscles of the leg. Anteriorly it reaches the border 

 of the obliquus externus abdominis muscle and posteriori}^ touches 

 the biceps, under which its duct passes. From al)ove downwards 

 it rests on the rectus, iliacus, gluteus minimus and g. medius 

 muscles. 



A gland of average size measured 3 cm. in length, 2 cm. in 

 breadth at its widest part, and about 1 -5 cm. in thickness. The 

 outline is somewhat reniform, the inner border being strongly 

 convex, and the outer marked by a deep indentation about its 

 middle, somewhat resembling the hilus of a kidney. The ends 

 are rounded ; the anterior is larger and thicker and is directed out- 

 wards ; the posterior is smaller and thinner, and directed backwards. 

 It is flattened dorso-ventrally, the dorsal surface being slightly 

 convex and the ventral flatter. The surfaces show the lobular 

 character of the gland. From the posterior half of the outer 

 border the duct emerges, and passes downwards, with the nerves 

 and vessels, on the posterior aspect of the leg. It is about 5 cm. 

 in average length, and in an undilated state about 2 mm. in 

 external diameter. After leaving the gland it passes down under 

 the biceps muscle, internally to the tendons of the tibialis 

 posticus and flexor longus hallucis muscles, then crossing obliquely 

 the tendon of the gastrocnemius, reaches the base of the spur. 

 Here it becomes dilated into a sac which is so deeply embedded 

 in the ligamentous tissue at the ])ack of the tarsus that its 

 isolation is a matter of ditiiculty. From this dilatation a prolonga- 

 tion extends into the canal in the spur. (PI. x.wiii.) 



The nature of the spur has already been sufticiently well 

 indicated. It is attached to a supernumerary tarsal ossicle which 

 is articulated to the astragalus and tibia. The powerful gluteus 

 maximus is inserted at the base of the spur, and is in all pro- 

 lyl )ility the muscle brought into action when the animal "strikes." 



Histohgy of the Gland and Duct. 



The minute structure of the gland and duct was studied in 

 specimens from three adult individuals shot near Raymond 

 Terrace, N.S.W., on June 6th, 1894. They had been placed in 



