36 FRANKLIN PARADISE JOHNSON 



epithelium of the zona intermedia is much thicker than that of the 

 zona columnaris and shows only a slight amount of cornification. 

 This, however, increases when followed downward so that at the 

 ano-cutaneous line the stratum corneum is as thick as that of the 

 zona cutanea. The description of the ''zona cutanee lisse" of 

 Robin and Cadiat is in agreement with what is found in the zona 

 intermedia at birth. It is a smooth zone, contains no hair folli- 

 cles, sebaceous or sweat glands and only a few dermal papillae. 

 These latter are found only in the lower part of the zone. The 

 ano-cutaneous line is arbitrarily placed at the point where the 

 hair follicles and sebaceous glands begin to appear. A short 

 distance beyond this point are found numerous sweat glands, 

 which represent the circumanal glands of Gay. 



Intramuscular glands were found in series 10.20, 10.21 and 

 10.22. In all three series they arise from the bottoms of the out- 

 foldings of the zona columnaris. In structure they are similar to 

 those seen at 240 mm. Although evidences of secretory cells are 

 rare in these glands at birth, few were seen in different places. 



No intramuscular glands were found in series 10.8 and 10.23 

 but as these series only contained a few sections each, it is not 

 improbable that the glands were present in the specimens but 

 that none happened to be cut through in these sections. 



No marked differences were observed in the outer coats of the 

 rectum. In 10.22 distinct but small bundles of striated muscle 

 fibers were seen extending up from the external sphincter muscle 

 into the folds of the zona columnaris. In some instances these 

 fibers are closely grouped together; in others, they are more 

 widely separated. About six groups in all were present, contain- 

 ing from ten to tw^enty-five fibers each. In none of the other 

 series were similar fibers found. 



In all the rectums at birth the muscularis mucosae is distinct 

 in the region of the ampulla but cannot be distinctly traced down 

 as muscle columns in the large mucosal folds. As in the preced- 

 ing stages, a few fibers of this muscle layer can be traced below the 

 ano-rectal line into the zona columnaris. These lie quite close to 

 the epithelium and in the lower part of the zona columnaris 

 become lost in the connective tissue. 



