Mervin T. Sudler 405 



nearer the middle line. From below, the cavity of the tongue is the 

 largest feature. The larynx, as has already been stated, is plugged, but 

 there is a large transverse projection corresponding to the arms of the 

 T mentioned in describing the preceding models. 



Umhrijo XLIII. 

 This embryo has a neck-breach length of l-i mm. and a vertex-breach 

 of 16 mm. It is an emln-vo of the 6th week. This model also includes 



Fig. 10. Lateral view of the model of the mouth and nose of embrj'o XXII. 

 Magnified 10 diameters. N., nasal cavity; Oe., nesophagus; Sub. mx. gl., rudiment 

 of the submaxillary gland; Thym., thymus; Tr., trachea; Thyr., thyroid ; T. p.', 

 nferior turbinate process ; T. p.'^, middle turbinate process. 



the epithelium excejit in the larynx where the plug is left out in order 

 to show its position. This model is so like the preceding one just 

 described that there is no need of a detailed description. The differ- 

 ences most striking: in a side view of the model, as seen in Fig. 9, are 

 the complete closure of the larynx by the epithelial plug; the lowered 

 position of the thyroid and thymus rudiments; and the appearance of 

 the rudiment of the submaxillary glands. The 1st visceral pouch 

 (Eustachian tube) is bent upwards and the ridge running inward is still 

 recognizable. In this view the nasal cavity is represented l)y an angular 



