1120 



F. MÛLLER UND P. SPRUMONT 



SUMMARY 



1. The development of the Aditus laryngis occurs simultaneously with that ofi 

 the pulmonary primordium. Both anlagen dérive from evaginations fromi 

 the oesophagus. 



2. The opening of the Aditus laryngis takes place at approximately the 15thl 

 development day because of the initial fonction of the laryngeal dilatator| 

 muscle which appeared a short time before. The phenomenon is in relation 

 with the ventilation of the initially collapsed lungs. 



3. The microscopic observation of the sections from our material allows to 

 recognize a later closing of the laryngeal entrance which occurs after the 

 ventilation of the lungs; this very fréquent finding is related to a particular 

 functional state and not to a cellular fusion. 



LITERATUR 



BovÉ, F. J. 1967. MS-222 Sandoz. L'anesthésiqiie et tranquillisant pour les poissons, 

 grenouilles et autres animaux à sang froid. Sandoz, Bâle. 



Gaupp, E. 1904. A. Eckers und R. Wiedersheims Anatomie des Frosches, aufgrund eigener 

 Untersuchungen durchaus neu bearbeitet. 3. Abt. Lehre von den Einge- 

 weiden, dem Integument und den Sinnesorganen. Organa respiratoria 

 propria, Vieweg F. Braunschweig: 164-200. 



Ladewig, p. 1944. Fine histologische Ubersichts- und Bindegewebsfàrbung. Schweiz. 

 Med. W. schr. 5: 132-133. 



LisoN, L. 1960. Histochimie et cytochimie animales, Baker (1946). Gauthier- Villars, 

 Paris: 755-756. 



Shumway, w. 1940. Stages in the normal development of Rana pipiens. 1. Fxternal form. 

 Anat. Rec. 78: 139-147. 

 — 1942. 2. Identification of the stages from sectioned material. Anat. Rec. 83 : 309-3 1 5. 



