SUPRA-RENAL CAPSULES. 



839 



appear to behave differently. Part of them 

 by bursting arrive at the end of their career. 

 They do not become distended with secretion 

 a second time, but the gland- vesicles cease to 

 exist as such in consequence of further meta- 

 morphosis. The ovary, the vesicles of which 

 disappear by the formation of a corpus luteum, 

 affords a proof of the occurrence of this pro- 

 cess. While, on the contrary, other gland- 

 vesicles seem to close again, and to become 

 distended with new secretion, in order to their 

 going through the process for a second or 

 perhaps a third time. It is exceedingly diffi- 

 cult to come at the truth respecting this matter, 

 but an examination of the Peyerian glands may 

 afford us some help in the investigation. 



Each Peyerian patch consists of but a single 

 layer of gland- vesicles, which in the adult ap- 

 pear all to be at pretty much the same stage 

 of development. No second row of unde- 

 veloped vesicles is ever found beneath this 

 layer, such as might be supposed to serve as 

 a compensation for those which have burst ; 

 so that a Peyerian patch of glands, after all 

 the vesicles had burst, would necessarily dis- 

 appear, if no closure of the vesicles followed, 

 unless indeed a power existed to develop a 

 new group of vesicles at some other point. 

 Now although the Peyerian glands of Man and 

 Mammalia certainly show individual varieties 

 in number and extent, yet these appear too 

 small to prove a destruction of the Peyerian 

 vesicles after the mariner of the Graafian fol- 

 licles of the ovary. Besides this, I have never 

 been able to remark the least appearance which 

 could lead me to imagine a new development 

 of the glandular patches. Moreover, it is a 

 well ascertained fact, that in many Mammalia 

 certain Peyerian gland-patches show a con- 

 stant position and size at all periods. To this 

 category belongs a very large Peyerian patch 

 which exists in the rabbit at the point where 

 the ileum opens into the large intestine. 

 Such structures will scarce admit of any other 

 conclusion than that the gland-vesicles re- 

 close themselves after their dehiscence. 



From these observations, which in part de- 

 pend on researches not yet published, we 

 shall be able to come to a decision respecting 

 the glandular nature of the supra-renal cap- 

 sules. 



In them the same gland-cells appear ; the 

 same membrana propria, capable of with- 

 standing alkalies. Exteriorly this issurrounded 

 by capillaries, and interiorly it contains the 

 same mass, consisting of molecules of a protein 

 substance, fatty granules, nuclei, and cells de- 

 veloped by circumposition of a membrane. 

 We also find a development of gland-vesicles 

 from cells identical with that which was met 

 with in the Ammoccetes. The multiplication of 

 the nuclei here occurs by the method of fission. 

 And since, in the supra-renal capsules, these 

 undeveloped gland-vesicles occur in predomi- 

 nant quantify, we may, therefore, well imagine 

 that the old gland-vesicles are destroyed in 

 these organs, in which they undergo dehis- 

 cence. But their contents are not extruded 

 outwardly, as are those of the gland-vesicles 



previously described, but into the fibrous frame- 

 work of the organ, in which they exist in the 

 fluid form, and from which they are subse- 

 quently received into the vascular system 

 either by immediate or mediate resorption. 



We are therefore correct in regarding the 

 supra-renal capsules as glandular organs," and 

 their function as secretory ; and any hypo- 

 thesis which ascribes to them a function other 

 than secretory, may be safely considered erro- 

 neous. 



If we now address ourselves to a comparison 

 of the structure of the supra-renal capsules 

 with that of other vascular glands, we shall see 

 how great a resemblance obtains. 



Unfortunately, we do not possess such ex- 

 perimental researches regarding all of them 

 as those which Ecker has published in his 

 work on the supra-renal capsules. Only the 

 thymus gland has found an accurate observer 

 in Simon.* Nevertheless, we already know 

 thus much, that in two of the three other 

 vascular glands, viz., in the thymus and thy- 

 roid glands, a similar structure obtains. Bar- 

 delebenf was the first to observe what 

 Ecker |, Gerlach, Schaffner [|, and others 

 confirmed, that in the thyroid gland gland- 

 vesicles occur grouped in masses, imbedded 

 in a loose cellular tissue, and surrounded by 

 blood-vessels. In Man, they are seen with 

 some difficult}' ; but are more easily made 

 out in most of the Mammalia, and best in 

 Birds and Rcptilia. These vesicles, which 

 attain a size varying from G-lOOOlhs to 

 5-100ths of a line, begin as cells which mea- 

 sure 5 to I0-1000ths of a line, and which 

 are connected with them by all the transi- 

 tional forms. Suspended in a fluid which 

 occupies their interior, are varying numbers 

 of elementary granules of an albuminous 

 material ; and besides these, fatty granules, 

 nuclei of 2 to SOOOths of a line, and finally, 

 cells with one or more nuclei. In the earlier 

 periods of foetal life the vesicles are not to 

 be met with ; but their place is entirely oc- 

 cupied by cells, a condition exactly similar 

 to that which was met with in examining the 

 supra-renal capsules. 



So also the gland-vesicles of the thyroid 

 appear after some time to be destroyed, and 

 their contents resorbed. This is shown by 

 the fact, that frequently only younger and 

 undeveloped forms of these are to be met 

 with in the adult animal ; while in other in- 

 stances, the fully developed vesicles occur in 

 excessive numbers. Some distinction between 

 the thyroid and supra-renal capsules, although 

 not an important one, may possibly be de- 

 duced from the fact, that in most of the Mam- 

 malia, the nuclei and cells are ranged as an 

 epithelial stratum on the inner surface of the 

 vesicles, so that the remainder of their cavity 



* A Physiological Essay on the Thymus Gland, 

 London, 1845. 



t Observationes de glamlularum ductu excrctorio 

 carentium structura, lieroliiii, 1811. 



J Loc. cit. 



Loc. cit. 



|| Henle und Pfeuffer's Zeitschrift fur rationdlc 

 Medizin, 184D. 



3 ii 4 



