55 



ducts, (<r) the blood vessels and nerves (and ganglion), together 

 with the connective tissue. 



Study carefully the character of the cells composing the secret- 

 ing acini, noting (a) the structure and staining reaction of the cell- 

 body, (6) the position and structure of the nucleus. Can you find 

 a place where duct and secreting portion are continuous ? Recog- 

 nize the presence of demilunes and note the character of the cells. 



113. Serous type. Section of the parotid gland. Cat. Mer- 

 curic chlorid -f 5% glacial acetic acid (§ 26) ; paraffin ; sections 



/yi. Stain with hematoxylin and picrofuchsin. 

 Study the section for the general structural appearance and 

 lobulation, the secreting acini and ducts, blood vessels, nerves and 

 connective tissue. Study the acini carefully, comparing them with 

 the secreting acini in 112 as to the shape and size of the cells, the 

 position and structure of the nucleus, and the structure and appear- 

 ance of the cell bodies. What are the differences ? Can you dis- 

 tinguish mucous and serous glands ? Compare the glands you 

 found in the esophagus and soft palate. 



PANCRSAS. 



114. Pancreas. Horse. Assigned for study. Picro-forma- 

 lin ; paraffin ; hematoxylin and eosin. 



Examine the gross preparations for general appearance, lobula- 

 tion, compactness, color, etc. 



In studying the section analyze its structure in the same man- 

 ner as 112 and 113, observing carefully its general structural ap- 

 pearance, the ducts and secreting acini (tubules), the structure and 

 shape of the cells forming these, the position of the nucleus. Are 

 areas of lyangerhans present in the section ? Compare the section 

 with 113 as to (a) compactness, (6) shape of the secreting acini, 

 (c) the lumen of the acini. Can you distinguish them ? 



115. Zyrriogen granules. Pancreas. Calf. 1% osmic acid 

 (§22); paraffin; sections yu. No staining. 



In the ends of the cells forming the secreting acini (tubules) 

 observe the presence of light brown granules— trypsinogen gran- 

 ules, precursor of the ferment secreted by the gland. Compare 103. 



116. Injected pancreas. Rabbit. Blood vessels injected 

 with carmine gelatin mass ; alcohols ; collodion ; stain lightly with 

 hematoxylin. This preparation illustrates the vascularity of the 



