360 



STOMACH AND INTESTINE. 



as in some of the follicles of the Calf, 

 the cavity of the intestine is separated from 

 that of these minute sacs by the inter- 

 vention of a thick compound mucous mem- 

 brane, it is difficult to avoid the conclusion ; 

 that a transit of their fluid contents, in 

 either, direction can only obtain to a compa- 

 ratively small amount. 



In addition to these important relations 

 between the agminate follicle on the one 

 hand, and the vascular and intestinal cavi- 

 ties on the other, recent observations have 

 shown that there is a third, which is perhaps 

 quite as intimately connected with its func- 

 tion : namely, the connection of the follicle 

 with the commencement of the lacteal system. 

 For the general analogy of the intestinal 

 follicle to the vascular gland is far surpassed 

 by that close structural resemblance which 

 Koelliker has shown that it possesses to the 

 follicles of the lymphatic glands. The 

 latter, indeed, exhibit a remarkable similarity 

 to the structure of the agminate follicles. Like 

 them, they enclose vessels as well as cells, 

 within the cavity formed by their limitary wall. 

 Hitherto it has certainly been found impossible 

 to verify the presence of lacteals within the 

 agminate follicles; or to establish the existence 

 of any direct communication between their 

 cavities and that of the lacteal vessels them- 

 selves. But in spite of this, it seems 

 certain, both that the lacteals occupy the 

 patches in numbers quite disproportionate 

 to the small and few villi here present ; 

 and that they possess the closest proximity 

 with the contents of the follicles. Such a * 

 conclusion must, I think, be drawn from 

 Bruecke's researches ; in which the cavity of 

 the follicle soon became slightly coloured with 

 reddened turpentine, which had been injected 

 into the lacteals by compressing the distended 

 intestine. 



It remains, however, for future researches 

 to determine how far this view is correct, and 

 whether the agminate follicles do really par- 

 take of the nature and office of lymphatic 

 glands. In any case, their very variable 

 number, and their occasional absence, would 

 seem to indicate, that (like the similar struc- 

 tures always present in the tonsils, and some- 

 times found in large numbers within the mucous 

 membrane of the stomach) their function is 

 either not very important; or what is far 

 more likely can be more or less replaced by 

 that of other kindred organs. And from the 

 number and size of these follicles, we may 

 perhaps conjecture, that their merely quanti- 

 tative effect on the chemistry of the organism 

 is not very great. 



The little that is known of their changes 

 in health and disease confirms what has just 

 been stated respecting their relations to the 



* That direct communication between the agmi- 

 nate follicles and the lacteals, -which Bruecke de- 

 duced from his observations, is, however, contradicted 

 by the time at which the colour above mentioned 

 appeared, and by its diminished intensity of hue : 

 as well as by the fact, that the agminate follicle never 

 contains white chyle. 



vascular and lymphatic systems. Thus, dur- 

 ing digestion, they become so swollen, as 

 to project from the inner surface of the intes- 

 tine : a condition that may, perhaps, be due 

 to increased absorption from the intestine, but 

 is better ascribed to that energetic determina- 

 tion of blood to the whole of the intestinal 

 structures which then takes place. During 

 the violent drain of cholera the same tumid 

 condition obtains : probably from a similar 

 cause. And finally, the remarkable parallel 

 between the disease of these follicles and 

 that of the neighbouring mesenteric glands, 

 which is seen both in phthisis and typhoid 

 fever, is a strong additional argument for the 

 reality of that analogy which physiology indi- 

 cates to exist between the two structures. 



Solitary follicles. The solitary follicles are 

 so completely what their name implies 

 isolated structures of the same kind as those 

 which are aggregated to form the "patch" 

 that any further description of their mi- 

 nute anatomy would be quite superfluous. 

 Indeed, those smaller patches which are 

 formed by two or three follicles, may be 

 almost regarded as a transition between the 

 "solitary" and" agminate" arrangement. But 

 these scattered solitary follicles are seldom 

 or never surrounded by a definite circle of the 

 apertures of intestinal tubes. And they often 

 sustain villi of the usual size and shape. 

 Their number is extremely variable. Some- 

 times they seem to be altogether absent. But 

 a very careful examination will now and then 

 show, that such a deficiency is one in appear- 

 ance only ; and is due to the very slight degree 

 of distention which obtains in the follicles 

 really present. Whether this explanation 

 would always hold good is more doubtful: 

 though the remarkable constancy with which 

 these structures are found in most animals 

 and in the human foetus is, to say the least, 

 a strong confirmation of its general truth. 

 In other instances they are strewn thickly 

 over the whole intestinal canal, from the 

 oesophagus to the anus. Such an excessive 

 development is perhaps strictly a morbid 

 phenomenon. But it is also capable of ex- 

 planation as a mere collective hypertrophy ; 

 an overgrowth which results in an increased 

 number of these minute organs, instead of 

 an increased size of each individual follicle. 

 Which of these two views is the more correct, 

 will only be decided when we know more 

 respecting their office. 



They usually occupy the whole of the small 

 and large intestine in considerable numbers. 

 They are, however, more numerous in the 

 latter of these two segments of the diges- 

 tive tube. And here they also present a 

 larger size, as well as what is generally a 

 deeper situation in the sub-mucous areolar 

 tissue. Hence the depression that indi- 

 cates the follicle in the small intestine is 

 exaggerated, in the large intestine, into a deep 

 fossa ; which, commencing by an aperture over 

 each follicle, widens as it passes downwards 

 between the opposed sides of a few contigu- 

 ous intestinal tubes, to terminate, near their 



