trans, vil. 

 gl. int. 



ctrc.m. 



m. lev. ani 



zona 

 columnaris 



zona 

 intermedia \ v^- 



I. ano-cut. 



foil, pili 

 gl.seb. 



zona cutanea 



Fig. 3 Longitudinal section through the pars analis recti. From a hunum 

 embryo of 1S7 mm. ampulla, ampulla recti; circ.m., and long.m., circular and 

 longitudinal layers of the muscularis; foll.pili, hair follicle; gl.int., intestinal 

 gland; gl.intrm., intramuscular gland; gl.seb., sebaceous gland; l.ano-cut., ano- 

 cutaneous line; l.ano-rec., ano-rectal line; l.sin., sinuous line; m.lev.ani., levator 

 ani muscle; exl.sph., external sphincter muscle of the anus; int.spJi., internal 

 sphincter muscle of the anus; irans.vil., transitory villus of the ampulla. 



28 



