112 



and a fibrous mucosa ; next is the muscular coat, composed 

 of an inner circular, and an outer longitudinal layer of 

 non-striped muscle cells; lastly an outer fibro-elastic 

 coat. Sketch under high power. 



(f) Mammary Gland. 



Small pieces taken from the mammary gland of a nursing bitch 

 were hardened in mercuric chloride, stained in Delafield's haema- 

 toxylin, embedded in paraffin, and sectioned. The sections were 

 fixed to cover glasses, counter-stained in eosin, dehydrated, and 

 cleared in oil of bergamot and xylol. Mount on Balsam. 



Study first under low power. Observe the acini of the 

 gland united into small lobules by fibrous tissue. Under 

 high power it will be seen that the acini are limited by a 

 membrana propria, and lined by a single layer of cubical or 

 polyhedral cells. In the protoplasm of these cells, fat 

 droplets, varying in size, are often seen. The nucleus is in 

 the outer part of the cell. The lumen of the acinus is 

 quite large, and often contains granules, droplets of fat, and 

 fragments of epithelium. Sketch a number of acini under 

 high power. 



DRAWINGS FOR LESSON XXIV. 



