194 DEVELOPMENT OF SALIVARY GLANDS IN THE DOMESTIC CAT 



Here the field drawn was too small to afford orientation marks, and in 

 piling the plates the smaller models were used as guides. Naturally 

 these reconstructions ha\-e no claim to more than approximate accuracy 

 of line. The graphic method was used in a few cases. 



In the description of the anlages several terms have been coined and 

 are used in a precise sense. It will be convenient to cite the more im- 

 portant here. The larger salivary glands, such as the parotid and sub- 

 maxillary, develop in the course of sulci and undergo a modified de- 

 velopment in consequence. These glands have been termed sulcal in 

 contradistinction to those which appear as simple sprouts from the 

 basal cells of the epithelium, which are called difiise. The anlages 

 of the sulcal glands are at their first appearance attached accurately to 

 the fundus of the sulcus ; this position is termed fiindal. Later they 

 undergo a displacement to one of the walls of the sulcus, to a parietal 

 position. It is important to distinguish between a solid epithelial 

 ridge, formed by prohferation of the basal cells, and a bUnd fold of the 

 epithelium involving all its layers and produced by the obUteration of 

 a sulcus. The former is here designated keel or crest, the \a.tttr flange. 



In the terms of direction applied to the developing mouth the flexure 

 of the head is disregarded, and the parts are conceived to be in the 

 adult position. 



The situation of the anlages with reference to the oral cavity is a 

 matter of fundamental importance in questions concerning the homol- 

 ogies of the definitive glands. It is. therefore, necessary to follow the 

 more conspicuous changes in the mouth during a considerable period 

 of its development, with the \iew of correlating the development of 

 the salivary glands more intimately with that of the entire oral cavity. 

 In order to shorten this necessary' but long digression, I have held my- 

 self excused from any but the most scanty references to the literature, 

 and this the more readily because few of the investigators have con- 

 cerned themselves with the rather minute details that are gemiane 

 to our topic, and of them only A. Pohlman,' among recent writers, has 

 chosen for his material embryos of the cat. His interesting paper, how- 

 ever, deals with major problems of interpretation, which are not, for 

 the most part, of immediate importance to the study of the salivary 



' Pohlmann, .\. H. igio. Die embryonale Metamorphose der Physiognomie und 

 der Mundhohle des Katzenkopfes. Morph. Jahrb. XLI. Leipzig. 



