Dean D. Lewis 191 



PLATE II. 



Fig. 4. — Transverse sectiort through the ligamentum cricothyreoideum 

 medium, showing the general direction of the elastic fibers composing it. 

 Bundles of vertical fibers are surrounded by horizontal fibers, which pass 

 toward the median line to meet corresponding fibers of the opposite side. In 

 this section the crico-thyroid artery is seen piercing the ligament. The direc- 

 tion of the fibers of the subepithelial elastic layer and their relation to the 

 ligament is shown. 



Fig. 5. — Transverse section through the larynx at the lower part of the 

 thyroid cartilage. 1. Thyroid cartilage. 2. Conus elasticus. 3. Cricoid car- 

 tilage. 4. Posterior crico-arytenoid muscle. 



PLATE III. 



Fig. 6. — Anterior part of preceding figure as seen under low power, showing 

 the mode of attachment of the elastic fibers of the conus to the thyroid carti- 

 lage, and the general direction of the fibers. 1. Thyroid cartilage. 2. Peri- 

 chondria! process by which the elastic fibers of the conus are attached to the 

 cartilage. 3. Anterior part of the conus elasticus. 4. Subepithelial elastic 

 layer. 



Fig. 7. — Transverse section through the larynx at the level of the ligamenta 

 vocalia. 1. Thyroid cartilage. 2. Perichondrial process by which the elastic 

 fibers attach. This is the median process described by Gerhardt. 3. Nodulus 

 vocalis (cartilaginous nodule described by Mayer). 4. Ligamentum vocale. 

 5. Processus vocalis of the arytenoid cartilage. 6. Arytenoid cartilage. 7. 

 Ventricle of larynx. 



PLATE IV. 



Fig. 8. — Transverse section through the larynx at the level of the attach- 

 ment of the anterior extremities of the ligamenta vocalia — low power. 1. 

 Thyroid cartilage. 2. Thickened perichondrium described by Gerhardt as the 

 processus vocalis of the thyroid cartilage. 3. Nodulus vocalis (cartilago sesa- 

 moidea anterior) ; anastomosing bundles of elastic fibers pass off from it 

 anteriorly to be attached to the horizontal fibers of the perichondrium. 4. 

 Parallel elastic fibers of the ligamentum vocale passing into the posterior 

 extremity of the nodulus vocalis. 



Fig. 9. — Transverse section through the anterior attachment of the ligamen- 

 tum vocale. The larynx is divided in the median line. Low power: Van 

 Gieson's picro-fuchsin. 1. Thyroid cartilage. 2. Perichondrial fibers. 3. 

 Nodulus vocalis, showing numerous round and spindle cells. ,4. Musculus 

 vocalis. 



PLATE V. 



Fig. 10. Transverse section through the larynx at the level of the ligamen- 

 tum ventriculare. 1. Thyroid cartilage. 2. Cricoid cartilage. 3. Ligamen- 

 tum ventriculare. 4. Fibers of the ligamentum thyreoepiglotticum. 5. Ven- 

 triculus laryngis. 6. Group of glands. 



Fig. 11. — Transverse section through the epiglottis. 



