Joseph Marshall Flint 281 



same size to give rise to the same number of branches, this is by no 

 means so definite and well marked as it is in the case of blood-vessels. 

 In the submaxillary gland the following general quantitative relations 

 are found in the successive ramifications of the ducts. 



The Ductus Submaxillaris divides into 

 3 Primary Ducts which divide into 

 18 Interlobular Ducts Avhich divide into 

 96 Sublobular Ducts which divide into 



1500 Lobular Ducts. 



Obviously a table of this nature must be interpreted liberally inas- 

 much as it indicates only the average scheme of division in a system 

 which varies within wide limits. As an absolute standard it is worth- 

 less, its chief service being to indicate the general plan of ramification 

 of the ducts, estimated from corrosion preparations of several glands. 

 Since the lobules are always drained by a single duct we find from the 

 above table that there must be approximately 1500 lobules in the entire 

 submaxillary gland. 



In the corrosions one is often struck by an apparent similarity be- 

 tween the ducts of the lobule. and the ducts of the gland as a Avhole, 

 the former appearing much like a miniature reproduction of the latter. 

 When attention is called to this analogy it becomes immediately patent 

 and may, indeed, be extended to many other features of the gland as 

 we shall have occasion to show later. The duct enters the gland at the 

 hilus; the lobular duct passes into the lobule through a similar portal. 

 There is but one submaxillary duct to each gland; there is likewise but 

 one lobular duct to each lobule. In the gland the ducts ramify through 

 the central portion without ever reaching the capsule, keeping, indeed, 

 as far away from it as the anatomical conditions which require the drain- 

 age of the whole gland will permit. In the lobule the intralobular ducts' 

 take the same course with reference to the Memb'rana limitans and 

 and the drainage of the lobular alveoli. This analogy may be of more 

 interest than importance. Its explanation affords no difficulty since 

 the lobular and intralobular duets are formed by the same laws of 

 growth and mechanics of development which give rise to the larger 

 ducts of the gland as a whole. 



The Ducts in Sections and Digested Pkeparations. 



In preparations made by the method of piece digestion which have 

 been cleared by glycerine, xyol or creosote, the form of the lobule, the 

 frame-work, and particularly the distribution of the interlobular and 



