28 



H. LISSER 



ies were undertaken, and to Mr. Max Broedel for valuable sugges- 

 tions regarding some of the illustrations. 



I have included a large number of drawings in the hope that they 

 would help to make lucid the descriptions of the various struc- 

 tures involved. Accuracy and fidelity to the original sections 

 has alwaj's been the main object. However, it must be said, that 

 in reproducing embryonic tissue, peculiar difficulties are encoun- 

 tered. Condensed mesenchyma is not as a rule clearly outlined, 

 but shades gradually into the surrounding tissue, so that some 

 exaggeration is permissible, and in fact necessary in giving sharp 

 clear outlines to such structures for proper interpretations and the 

 construction of models. 



The embryos were cut in various planes, sagittal, transverse, 

 and frontal, thereby affording better opportunities for study. 

 They include the following: 



Each section in the laryngeal region was carefully studied, pro- 

 jected to sufficient magnification, and the different structures 

 outlined and identified. Recourse was then had to wax model 

 reconstruction, and to the several well known graphic methods of 

 reconstruction.^ 



I have purposely omitted any consideration of the vascular 

 development of this region, as reconstruction methods in embryos 

 are somewhat hazardous for such purposes. The modern injection 

 methods are far more accurate. Much remains to be done in this 

 section. 



1 24th Session. Amer. Assoc, of Anat., Baltimore, Md., December 1908-January 

 1909. Lisser: Models to show development of human larynx. 



