292 TOKUYASU KUDO 
This simple interpretation of the genesis of the macula neglecta 
has been considerably complicated by the studies of P. and F. 
Sarasin, who claim to have found a second endorgan in the 
Caecillidae, for they distinguish two different maculae, one of 
which lies in a small evagination of the sacculus (macula neglecta 
of Retzius), the other in the floor of the utriculus (macula neglecta 
fundi utriculi). The existence of the latter was, however, denied 
by Retzius, in which opinion he is joined by Ayers. Retzius 
states: ‘Hs geht nicht hervor, dass die am Boden des Utriculus 
der Caeciliiden gefundene Nervendstelle einer neu entdeckten 
Nervendstelle entspricht. Denn gerade am Boden des Utriculus 
liegt die von mir bei vielen Fischen, Reptilien und Vogeln ent- 
deckte Nervendstelle, Welche von mir schon laingst ‘Macula 
neglecta’ genannt wurde. Hsist deshalb ganz unrichtig, wenn die 
Herren Sarasin die von ihnen bei Ichthyophis am Boden des 
Utriculis beschriebene Nervendstelle als von ihnen neu entdeckt 
bet achten und sie als eine ‘Macula fundi utriculi’ auffiihren. 
Die echte ‘Macula neglecta’ liegt am Boden des Utriculus oder 
Offnung des Canalis,utriculo-saccularis, oder auch-nach meiner 
Ansicht—bei den niederen Amphibien in der eigentiimlichen 
Ausstiilpung dieses Canalis, welches ich ‘Pars neglecta’ gen- 
nannt habe, bei den héheren aber in einer von ihm abgetrennten 
Ausstiilpung der Sacculuswand.” He adds that it would be 
interesting to know whether both of the endorgans as described 
by P. and F. Sarasin really do occur, in view of the fact that in all 
Amphibia that have been thoroughly studied a single macula 
neglecta occurs. Ayers contends that the new endorgan of the 
Sarasins is probably none other than the macula neglecta of 
Retzius. But Fleissig, from his study on the development of the 
labyrinth in Gecko, was able to demonstrate a transitional con- 
dition between the two described above. According to this 
author the macula neglecta of Retzius is to be regarded as a 
persisting organ in the sinus inferior, while only traces of the 
macula neglecta of the Sarasins occurs in adult individuals; and 
these traces may Well be regarded as vestiges of Sarasin’s macula, 
which is present as a developing organ only at a certain stage. 
