274 H. WILDER, 



Part II. Muscles. 



1) The respiratory muscles of Necturus, with suggestions con- 

 cerning their primitive homologies. 



2) The respiratory muscular system of the other Urodeles. 



a) Introduction. General homologies. 



b) Extrinsic muscles. 



c) Intrinsic muscles ; the laryngeal ring. 



3) The laryngeal muscles of the Anura. 



aj The laryngeal anatomy of Rana, with sketch of deve- 

 lopment. 



b) Nomenclature of laryngeal muscles. 



c) Comparison of different Anuran forms. 



4) Summary of Part II. 



The following investigations on the Amphibian larynx were com- 

 menced by me while a student in the Morphological Laboratory of 

 Prof. Robert Wiedersheim in Freiburg i. Br. during the spring of 

 1891. To this I was led by the study of cross-sections through the 

 laryngeal region of Siren lacertina, which suggested to me a possible 

 theory of origin of the primary pair of laryngeal cartilages (No. 11, 

 p. 680 — 681) ^). More extensive investigation proved the artificial 

 character of this theory and led me to adopt my present idea of the 

 identity of this primary pair with the 5^'' branchial arches, or a 

 portion of them. This idea was communicated at that time to my 

 teacher, Prof. Wiedersheim, although the circumstance attending the 

 return to America and the acceptance of a position there, rendered 

 it impossible to publish it until the following year (1892, No. 12), 

 at which time the same theory was advanced by Gegenbaur in an 

 extensive treatise on the epiglottis (No. 5). It does not seem pos- 

 sible now for me to find out at what time this work is appeared in 

 Germany, but the first notice of it in the "Anatomischer Anzeiger" 

 was in the number of July 23, 1892, three mouths after the writing 

 of my article which bears the date of April 27, 1892. In this I do 

 not attempt to claim priority but wish to show that the conclusion 

 was formed independently of the work of Gegenbaur"). The foUow- 



1) The bracketed numbers refer to the bibliography. 



2) The advisibility of this explanation is shown by the following 

 rather remarkable statement of Göppkkt (No. 7). Speaking of an idea 



