DUCTLESS GLANDS. ccxxvii 



resembling those of the blood ; others are described as containing many 

 nuclei, and much granular matter. 



These being the general characters of the ductless glands, the varieties 

 met with in the human body may be arranged as follows. 



a. Rounded and closed capsules filled with nucleated cells, nuclei, and 

 intercellular fluid, and traversed by blood-capillaries ; the capsules placed 

 singly or in flat patches under a mucous membrane (solitary and agminated 

 intestinal glands), or surrounding a simple or complex recess lined by and 

 opening on the surface of a mucous membrane (certain lingual and pharyn- 

 geal glands, and tonsils) ; it being uncertain whether the contents of the 

 capsules are discharged by rupture or transudation, or taken up by 

 absorption. 



6. A lobulated organ inclosing a sinuous internal cavity, with no outlet, 

 filled with a liquid secretion containing corpuscles ; the cavity branching 

 into the lobules, and ending in the smallest of them, according to one 

 opinion, by groups of saccular dilatations of its membraua propria, covered 

 outwardly by capillary blood-vessels, as in the racemose secreting glands. 

 According to another view the walls of the cavity in an ultimate lobule are 

 not set round with saccules, but with small solid pellets, formed of aggre- 

 gated corpuscles similar to those of the fluid, and bounded towards the 

 outer surface of the lobule by a mernbrana propria, within which is a group 

 of blood-vessels pervading the corpuscular matter, as in a, (thymus). 



c. A glandular body containing different-sized locular spaces formed by a 

 stroma of fibrous or more or less homogeneous connective tissue : the loculi 

 containing granules, nuclei, and nucleated cells of various sizes, with inter- 

 cellular fluid (anterior lobe of the pituitary body and suprarenal capsules), 

 or lined by a membrana propria and epithelium, and filled with clear 

 tenacious fluid (thyroid body). 



d. An organ containing a peculiar pulp lodged in the interstices of a 

 trabecular and highly vascular structure ; also capsules with contents as in 

 a, attached to the vessels, and surrounded by the pulp, which, while con- 

 taining collections of red blood-corpuscles in various conditions, resembles 

 generally in nature the matter within the capsules, and is likewise traversed 

 by fine blood- vessels (spleen). 



e. Rounded or oval bodies having in their interior intercommunicating 

 loculi and intertrabecular spaces, further subdivided by retiform tissue, and 

 partially occupied by a corpuscular gland-pulp traversed by blood-capillaries ; 

 everywhere round the pulp a space left for the passage of lymph, communi- 

 cating with the afferent and efferent lymphatics (lymphatic glands). 



The purposes fulfilled by most of the organs referred to are still involved 

 in great obscurity, and very different opinions are held on the subject by 

 eminent authorities in Physiology. 



