Il6 PRIMATE ALVEOLINGUAL SALIVARY AREA 



3. The adult inter- and sub-mandibular salivarj- structures in the 

 lower primates. 



4. In view of the unavoidable limitations of these sources of infor- 

 mation it seems not only permissible but desirable to enlarge the 

 \-iewpoint by a critical comparison of primate conditions with those 

 found both in the adult and embryo of other mammalian orders. 



It will, however, be obvious that a generalized morphological analy- 

 sis of the primate salivary tield here concerned can, in the absence of 

 definite ontogenetic information on many important and critical 

 points, possess at best only a tentative value, and must remain subject 

 to further re\dsion, as the material for its completion and correction 

 may become available. 



In seeking for a satisfactory interpretation of the widely diversified 

 glandular organization encountered in adult primates, and, secondarily, 

 in adults of other mammalian orders, the observer becomes convinced 

 that in spite of the multiplicity of the types, often diflfering materially 

 on the two sides of the same indi\'idual, some inherent genetic ground 

 plan is common to all grades of variation and combination, and that 

 the estabhshment of adult sub- and inter-mandibular salivary homol- 

 ogies in mammals must be based on the definition of a comprehensive 

 potential genetic field in which ontogenetic and phylogenetic selection 

 becomes responsible for the development of the individual types of the 

 adult animal. In other words, the same genetic method, which has 

 made the interpretation of the closely interlocked axial vascular chan- 

 nels of adult mammalia possible, may prove of equal service in clari- 

 fying the involved problem of the mutual relations of mammalian 

 saUvary glands. 



This result might be achieved by adopting the following procedure : 



1. The establishment of a general theoretical dogma of salivary 

 .development within a plastic and uniform ontogenetic and phylo- 

 genetic framework, which would include all indiA'idual types and allow 

 such individual t}'pes to evolve from the common comprehensive 

 ground plan by embryonic selection and further development of typical 

 districts, with suppression of the intervening areas. 



2. The ahgnment of actually recorded adult conditions within the 

 appropriate sections of the common framework, thus permitting close 

 analysis of divergent types. 



