AUTHOR’S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, JUNE 1 
ON THE DEVELOPMENT OF THE NERVE ENDORGANS 
IN THE EAR OF TRIGONOCEPHALUS JAPONICUS 
TOKUYASU KUDO 
Anatomical Institute, Medical High School, Niigata, Echigo, Japan 
ONE PLATE 
The endorgans of the auditory nerve in reptiles have been 
investigated morphologically with considerable thoroughness. 
Many authors have interested themselves particularly in the 
macula neglecta (described for the Amphibia by Deiters in 1862 
and given the name now in common use by Retzius) and this 
endorgan has been studied in various vertebrates, especially in 
the fishes, the Sauropsida, the mammals and even in man. 
Relatively few embryological investigations, however, have 
been published on this subject. Concerning the genesis of the 
macula neglecta, Retzius and Alexander concluded that this 
organ originates from the crista acustica posterior, the former 
basing his opinion on its comparative anatomy and the latter on 
observations of its innervation. In Hertwig’s Handbuch Krause 
briefly states that a small region of common neuroepithelium 
differentiates upon the separation of the saccular from the 
utricular portions. Fleissig, who, working on reptiles (Gecko), 
was the first to investigate extensively the development of the 
macula neglecta, disagrees with both of these statements and is of 
the opinion that the organ arises from the macula sacculi. The 
same conclusion is reached by Okagima in the case of Hynobius; 
but this author remarks that because in the Amphibia the macula 
neglecta lies within the sacculus, its origin in these forms is easier 
to determine than in the reptiles, where the macula is found in the 
utriculus. Corroboration of this view, according to which the 
macula neglecta arises from the neuroepithelium of the pars in- 
ferior, is found in Okagima’s study of the salmon embryo and 
Wenig’s recent work on Pelobates fuscus. 
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