334 MAMMALIAN ALVEOLINGUAL SALIVARY AREA 



long been available, Gegenbauer expressly states "that we must take 

 the orifices of glands to be the portions first formed." If it thus seems 

 that anatomists are somewhat impervious to information derived from 

 the developmental field, and persist in the endeavor to solve the prob- 

 lems of morphology without the aid of ontogeny, the case is hardly 

 better with the embryologist, who sometimes seems unaware that prob- 

 lems of homology exist at all. The effects of one-sidedness are as un- 

 fortunate in the one disciphne as in the other, and appear as con- 

 spicuously from the developmental as from the comparative standpoint. 

 It was the merit of Carmalt to perceive the importance of a return to 

 the larger method of morphology, and he was on the point of beginning 

 a developmental study of the sahvary glands, when his useful and stimu- 

 lating labors were brought to an untimely close. 



Before examining the developmental literature, it will be convenient 

 to define the sulci of the alveolingual region, Regio alveohnguahs, which 

 itself forms the zone of junction between the circumhngual space and 

 the marginal portion of the oral cavity, and corresponds to the crest of 

 the palate process. Its floor, the alveohngual gutter (sulcus alveolohn- 

 gualis, Chie\itz, Hammar), is a concavity extending from the tongue 

 laterad to the region of the alveolar process. It presents four sulci, 

 which vary in degree of development in embryos of different forms. 



1. Sulcus lingualis (Schulte). This appears to be constant. In it 

 three segments may be distinguished, cranial, intermediate, and caudal, 

 the last corresponding topographically to the submaxillary ganglion; 

 and serving as the point of inception of the submaxillary anlage. 

 This furrow defines the alveolingual region against the tongue. Its 

 course is in general sagittal, but its cranial segment turns mesad beside 

 the frenulum, in front of which it is confluent with its fellow of the 

 opposite side. In time of appearance it antedates the other sulci of 

 this region. 



2. Sulcus alveolaris (Schulte) ; sulcus sublingualis (His). This 

 forms the lateral boundary of the alveolingual gutter. In man it is 

 deep and cleftlike (His). It has a nearly sagittal course, beginning 

 at a point caudad of the lingual nerve and extending beyond the sym- 

 physis. Its anterior extremity crosses Meckel's cartilage dorsally and, 

 reaching a point lateral to the cartilage, gradually is lost. This portion 



