THE DUCTLESS GLANDS. 
3y D. J. CUNNINGHAM. 
Unper this title we include a heterogeneous group of organs, the common feature 
of which is that the products of their activity are not conveyed from them by 
means of ducts, but are discharged directly into the vascular system through the 
veins or ly mphatic vessels which take origin within them. This phy siological 
process is termed internal secretion, and in the case of certain of these organs the 
secretion has been shown to exert a profound influence upon the nutritive “changes 
of the body. 
The duetless glands include the lymphatic glands, which have been already 
described with the vascular system; the pineal ‘and pituitary bodies, which have 
been referred to in the account which has been given of the brain: and the spleen, 
the suprarenal capsules, the thyroid body, the parathyroids, the thymus body, the 
coceygeal body, the carotid body—all of which still remain to be studied. 
THE SPLEEN. 
The spleen (lien) is the largest of the ductless glands. It varies greatly in size 
in different individuals, and also in the same individual under different conditions, 
consequently it is difficult to give its average dimensions. Roughly speaking, it may 
be said to be as a rule about five inches in length and three inches in width at its 
widest part. It isa soft yielding organ, very vascular, and somewhat purple in 
colour. It lies far back in the abdominal cavity between the stomach and the 
diaphragm, and its position is such that, whilst the greater part of the organ is 
situated in the left hypochondrium, its upper end extends inwards beyond the left 
Poupart plane, and thus comes to lie in the epigastric region. It is placed very 
obliquely, and its long axis corresponds closely in its direction to that of the 
back part of the tenth “ib. 
Form of Relations of the Spleen.—The spleen has the shape of an irregular 
tetrahedron. The upper end or apex (extremitas superior) points inwards and 
backwards, and is curved to some extent forwards on itself. Of the four surfaces 
the most extensive is the diaphragmatic (facies diaphragmatica), which looks back- 
wards and outwards. It rests upon the back part of the diaphragm, to the curvature 
of which it is accurately adapted. By the diaphragm it is separated from the ninth, 
tenth, and eleventh ribs. It is necessary also to remember that the pleura descends 
between this portion of the chest wall and the diaphragm, and thus comes to lie 
superficially to the greater part of this diaphragmatic surface of the spleen. The 
thin basal margin of the lung, which occupies the upper part of the pleural recess, 
likewise intervenes between the upper part of the spleen and the surface of the 
body. 
In the fcetus and infant, in which the liver is relatively very large, the left lobe of that organ 
extends to the left so far that it comes as a rule to intervene between a portion of the spleen and 
the diaphragm. Such a relation is sometimes seen in the adult, but, except in childhood, it is 
usual for the liver to fall short of the spleen. 
‘ 
