Since the chemical constitution of the se cretion is unknown to us, we are unable to state either the object of the vascular glands in general, or that of the supra-renal capsules in particular. Pathological study also has, up to the present time, failed to afford any thing which would allow any safe conclu sion to be drawn concerning the function of the supra-renal capsules. By their concealed situation, they elude the experiments of the physiologist ; besides this, they are so small, that their secretion can scarcely have any very sudden and visible influence on the vegetative life of the body. So that even by such an eager operative interference as the extirpation of this gland, the wished-for result might scarcely be obtained.
I therefore repeat, that at present we are completely in the dark as to the function of the supra-renal capsules ; we know not at all in what way they operate, and on this account all references of the supra-renal capsules to this or that organ — such as have so often been made—are altogether empty and worth less. We may see at a glance that it would be just as correct to assign a relation of the supra-renal capsules to the eye or ear, as to the sexual or urinary organs.
Ecker, who, in opposition to our view, re gards the secretion of all the vascular glands as one and the same, keeps its contents of fat and protein compound especially in view, and conjectures that all the vascular glands are adapted to the formation from the blood of a secretion which is rich in protein and fat, and which being subsequently retaken into the current of the blood, in this manner benefits nutrition. But apart from the fact, that one
cannot see why such a fluid should take this round-about way through the vascular glands ; apart from this, the quantity of protein com pounds in the secretion of all the vascular glands of the body, even if we take this at the highest estimate, is far too small to render any enrichment of albuminous materials which the body could obtain in this way other than a very inconsiderable one. The want of an excretory duct affords certainly this informa tion, that the secretion prepared by the vesicles of the vascular glands is again received into the blood ; but even this notion has connected with it much that is obscure and uncertain.
The difference of the function of the vascular glands is yet further upheld by the circum stance that their vital duration and activity is different. The function of the thymus is the first to wane ; that of the supra-renal capsules seems likewise much diminished in more advanced age ; while, on the contrary, the activity of the spleen endures for the whole life. These organs experience an excessive deposit of fat in their vesicles, and by this means gradually disappear.
(Heinrich Frey.)