1210 



ME. R. I. POCOCK ON THE EXTERNAL CHARACTERS 



remote from the aims, are tlie apertures of the anal glaiick. 

 Each of the apertures of the anal glands leads into a deep 

 narrow pouch, at the bottom of which are three papillte, each 

 tipped with a long hair. This pouch can be evaginated, so that 

 tlie gland comes to the surface, and the strong-smelling secretion 



Text-figure 60. 

 J. 



A. Diagrammatic dissection of the aiiua and genitalia of male Castor canadensis. 



B. The same of the female. 



C. The cloaca of the male, opened. 



D. „ „ „ ,, female ,, 



E. One of the anal glands, showing the tip with its papillfe and setaj within 



the pouch. 

 t, testis; s, pubic suture; p, penis; c, castorium glands with orifices on 

 each side of preputial orifice in male and above vaginal orifice in female ; 

 V, vaginal orifice ; ag, anal gland ; o, orifice of anal gland ; a, anus ; si, 

 slit through which secretion of castorium glands is discharged into cloaca 

 in female. 



is discharged at the tips of the papillfe. ISTormally the penis is 

 completely retracted, but it is capable of being protruded through 

 tlie orifice a.bove mientioned into the cloaca and thence to the 

 exterior. Through this orifice the secretion of the castorium 



