SUPRA-RENAL CAPSULES. 



837 



distinct cortical and medullary substance. 

 But only part of the morphological consti- 

 tuents were present ; viz., the elementary 

 granules, fat, and nuclear structures. Cells, 

 with or without a membrane, were only 

 sparingly found ; and gland-vesicles were 

 altogether absent. The embryos of other 

 Mammalia exhibited the same results. In the 

 foetus of an ox of 1 A feet in length, the vesicles 

 were for the first time detected ; and in this 

 instance, as in those of the mature animals 

 previously described, the gland-vesicles were, 

 according to Ecker's opinion, developed from 

 enlarged cells. 



In any case it is exceedingly interesting to 

 observe, that in spite of the very early found- 

 ation of the supra-renal capsule, this organ 

 seems to rest for a considerable time ; since, 

 before their gland-vesicles are developed, we 

 cannot ascribe any activity to the supra -renal 

 capsules. But in man, these vesicles are 

 only developed when the period at which the 

 supra-renal capsules attain their greatest bulk 

 is long passed. 



IV. Physiology. Finally we apply our- 

 selves to the functional relations of the supra- 

 renal capsules. Unfortunately, as regards 

 the activity of the glands of blood-vessels, 

 they all veil themselves in an impenetrable ob- 

 scurity. The recent vast strides of Physiology 

 have passed over them without leaving any 

 traces ; the last ten years having only brought 

 some new hypotheses concerning the function 

 of these organs, and very doubtfully enriched 

 the already great number of older conjectures. 



It is not the aim of this essay either to 

 answer or to enumerate all that physicians of 

 earlier and later times have imagined as the 

 possible function of the supra-renal capsules. 

 These conjectures, for the most part ephemeral, 

 may be properly left to the history of ana- 

 tomico-physiological science ; and since we 

 willingly disclaim the intention to come for- 

 ward with a new hypothesis, we will only 

 call attention to some points of this mass of 

 matter. 



Now that the minute structure of the supra- 

 renal capsules is known, it becomes even more 

 important to dissent from the opinion of 

 Cuvier. He attributed to the supra-renal 

 capsules pretty much the same function as the 

 kidneys," because these two organs have much 

 similarity with each other, both in their form, 

 and in the tissues of which they are com- 

 posed." At present we know how great is 

 the diversity between the tissues of the two 

 organs. Besides, the want of an excretory 

 duct is another fact completely passed over 

 by Cuvier. The opinion of Meckel, that the 

 supra-renal capsules stand in depenclance with 

 the sexual functions, rests on just as little 

 foundation, and has been already confuted at 

 length by Nagel in his work. So also the 

 conjecture of Bergmann* and others accord- 

 ing to which the supra-renal capsules stand 

 in a very close relation to the nervous system 



* Bergmann, Dissertatio de glandulis supra- 

 renalibus, Gottingte, 1839. 



of the foetus is equally erroneous. We will 

 willingly admit the correctness of the observ- 

 ation, that in brainless monsters the supra- 

 renal capsules are generally deficient ; but we 

 are forced to add, that we cannot annex any 

 distinct notions to this close relation to the 

 nervous system. Besides, this would suppose 

 that the function of the supra-renal capsule 

 differed in the fcetus and in the adult animal ; 

 since certainly no one would seriously defend 

 such a relation of their function in the latter 

 case. And the support which this view seems 

 to receive from the structure of the supra-renal 

 capsules, is likewise only a fallacious one. At 

 one time, attention was drawn to the great 

 richness of the supra-renal capsules in nerves, 

 without reflecting that this is the case in only 

 one out of the four classes of vertebrate ani- 

 mals : and in the same way, the superficial like- 

 ness possessed by the gland-cells and ganglion 

 corpuscles was adduced in order to make out 

 the supra-renal capsule as a kind of ganglion. 

 This hypothesis was put aside by the dis- 

 covery of the gland-vesicles. And especially we 

 would briefly remark, that all those theories 

 which ascribe to the supra-renal capsules a 

 special import during embryonal life, have ori- 

 ginated from contemplating them in the human 

 foetus, in whom they are exceedingly large. Had 

 the supra-renal capsules of other animals been 

 kept in view, those opinions could scarcely 

 have been taken up ; and the special size of 

 these organs in the human embryo would have 

 been recognised for that which it really is, 

 an anomalous, isolated condition, which pos- 

 sibly stands in a causal relation with the swift 

 disappearance of the Wolffian bodies. And, 

 as we have already remarked, even apart 

 from this, the absence of the gland-vesicles 

 from the supra-renal capsules of the small 

 embryo is a fact which must not pass un- 

 noticed. 



We will, therefore, only attempt to answer 

 such physiological questions concerning the 

 supra-renal capsules which are possibly sus- 

 ceptible of solution, and defer their full under- 

 standing to the future. 



We will see whether the supra-renal cap- 

 sules in general can be called glands, and how 

 far they correspond with the other glands of 

 blood-vessels, with the thyroid, thymus, and 

 spleen. And then we may answer the ques- 

 tion, " whether the supra-renal capsules ge- 

 nerally eliminate a glandular secretion, and 

 whether this secretion is to be regarded as 

 similar or diverse in the whole of the vascular 

 glands ?" 



Microscopic anatomy has taught us to re- 

 cognise three kinds of form under which 

 glands are developed in the higher animals. 

 The first is a fine tube or canal of different 

 length ; the second is a small globular or 

 elongated sac, which is open at one end ; and 

 the third form is that of a globular and com- 

 pletely closed vesicle. A very delicate struc- 

 tureless membrane, the membrana propria, 

 forms the frame-work of all these glands ; and 

 it is distinguished by its insolubility in dilute 

 alkalies'. On its exterior, it is surrounded by 



3 H 3 



