ON THE LVMPIIATIC SYSTEM. 165 



stance, as described by Henle,^ Pttiiger,- and all other observers, 

 consists of relatively coarse tibrillae. I have shown ^ that these 

 rods or tibrilte are joined by short lateral branchlets into a 

 reticulum. I find this reticulated arrangement of the above 

 rods or fibrillar specially well marked in preparations prepared 

 in chromic acid, especially when the cells are viewed obliquely 

 or in the bird^s-eye view; with a good high magnifying power, 

 e.g. Zeiss's oil V^, I can make it out also in the profile view. 

 A second or outer layer of cells is, as a rule, present only in the 

 commencement of the intralobular ducts, and then only as com- 

 posed of few cells, i.e. cells occurring from place to place at 

 considerable intervals. 



J)istinct from these latter are the nucleated cells, being 

 spindle-shaped or staff-shaped looking or branched, each with a 

 flattened or angular nucleus, which are in connection with the 

 mcmbraua propria, and extend from this between the epithelial 

 cells, in some cases even forming a sort of an inner membrane 

 lining the lumen. This condition is well shown in some of the 

 intralobular ducts in the parotid of the rabbit and guinea-pig. 



With the cessation of the fibrillation of the outer part of the 

 cell-substance, the intralobular duct or the salivary tube as such 

 terminates, and its columnar epithelial cells change into poly- 

 hedral cells. 



According to the accepted view, as represented by Heidenhein 

 (Hermann's 'Physiologic,' vol. i, p. 25 and 26), the salivary 

 tube passes into the alveoli by the intercalated or intermediate 

 part, a fine tube, which is either lined with long spindle-shaped 

 cells (parotid) '^ projecting " so far into the lumen of the alveoli, 

 that they are surrounded by the secretory cells like the stalk by 

 the apple (Boll, Ebner) ; or the intercalated part is lined with 

 small cubical cells, which pass suddenly into the large secretory 

 cells of the alveoli, as is the case in the submaxillary gland of 

 the dog and rabbit (Ebner). 



These statements of Ileidenhain, according to my observa- 

 tions, require sHght alterations and additions. 



(1) In the parotid of those animals that I have examined I 

 find that the salivary tube passes into the above intercalated or 

 intermediary part through a distinct narrow short bit, which I will 

 call the neck, and which is characterised by the lumen and the 

 whole breadth of the salivary tube becoming here suddenly 

 smaller, the lining epithelial cells more transparent, short cubical 

 or polyhedral, and very closely placed, and showing no signs of 



» ' Eingeweidelehre,' 1873. 



"^ 'Die Endig. d. Absonderungsncrven,' &c., Bonu, 18G6. 



^ ' Quarterly Journal of Micr. Sci.,' xix, 1879. 



