— 99 — 



carpfully removed, and suspended for several days in alcoliol, then 

 divided into small j)ieees, stained in borax carmine or Delafield's 

 liaMnatoxylin, embedded in paraHin, and sectioned. Fix to tlie 

 sl'de. and monnt in l)alsani. 



Sttuly lirst unil<'i- low })(»\vor, and notice the Ijronchi, 

 blood vessels, and alveoli. The sections of the Large 

 bronchi show a lining of stratified ciliated columnar epithe- 

 lium resting on a fibrous mucosa, in which small mucous 

 glands may be observed. Next, there is a band of non- 

 strijjcd mii-cle tissue, outside of which cartilage plates may 

 be seen in cross-section. The -mall bronchi are lined by a 

 single layer of ciliated columnar cells, and the cartilaginous 

 plates are wanting. Try and make out the capillaries 

 between the alveoli; a few blood cells may be seen in them. 

 Sketch a segment from the wall of a large bronchus; also 

 a small I)ronchiolc with a few of the surroundingalveoli, as 

 seen tinder high })ower. 



(gj Thyroid Gland. 



A piece of llie thyroid yland of a dog was iiardened in mercuric 

 cliloride, embedded in paraffin, sectioned, and fixed to cover 

 glasses. Tlie sections were tlien stained in lisematoxyhn and 

 eosin, dehydrated, and cleared in oil of bergamot and xylol. Mount 

 on balsam. 



Study first under low power. The gland is surrounded 

 by a fibrous capsule. Oval or round alveoli, lined by a 

 single layer of cubical cells, are seen. The alveoli are filled 

 with a substance which stains deeply in eosin. Sketch 

 several alveoli under high powder. 



