28 SPECIAL HISTOLOGY. 



and palate, the smallest lobes are surrounded in groups by 

 somewhat stronger sheaths of connective tissue, so that a 

 certain number of secondary lobes are formed, each of which 

 corresponds with a simple gland and also has the same size, 

 i. e. about I — If. 



The excretory ducts of the lobes have a coat of connective 

 tissue, with networks of fine elastic fibres, and a simple layer of 

 cylindrical cells 0008 — 0*01'" thick. In the principal excre- 

 tory ducts, the wall, which is very rich in elastic fibres, mea- 

 sures, even in the smallest glands, 0'02'", in the larger as much 

 as 003"' and 0-04'", the epithelium 0-01 —0-012'". Of muscular 

 fibres I saw no trace whatsoever, either in the glands them- 

 selves or in their excretory ducts ; on the other hand, they 

 possess many minute vessels, which penetrate with the excretory 

 duct or otherwise between the lobes, and form, in the interior, 

 a wide network of capillaries of 0003"', which encircle the 

 separate caeca and vesicles, so that each of them is in contact 

 with at least 3 — 4 capillaries. Nerves exist abundantly upon 

 the excretory ducts and, occasionally, moderately fine tubules 

 are found in the glands themselves. 



The secretion of the racemose glands is a clear, yellowish 

 mucus, with only accidentally intermingled granules, nuclei, 

 and remains of cells, which coagulates in acetic acid and 

 is insoluble in an excess of it, remaining as a viscid mass, 

 striated, or deceptively similar to a fibrous tissue. It fills the 

 excretory ducts and the other cavities of the gland to their 

 ultimate extremities, being readily rendered obvious in them 

 by acetic acid. I have never found the so-called mucous 

 corpuscles, as they exist in the fluids of the mouth, in a mucous 

 gland and I believe that, normally, the secretion of mucus goes 

 on without the production of cells. 



2.— FOLLICULAR GLANDS. 



§ 135. 



The follicular glands of the cavity of the mouth are : firstly, 

 simple follicles at the root of the tongue and, secondly, compound 

 follicles at the sides of the isthmus faucium, — the tonsils. These 

 organs agree so perfectly in structure, that the tonsils may be 



