356 



STOMACH AND INTESTINE. 



compound membrane forming the diffusive 

 septum in their experiments, would propor- 

 tionately favour the resulting transit of the 

 separated fluids. And since the continuous 

 movement of the chyle is probably aided by 

 forces independent of any mere act of dif- 

 fusion, the force of suction thus added must 

 itself conditionate a more active transit than 

 that which they witnessed in the inert en- 

 dosmometer. 



On the other hand, there are good reasons 

 for regarding the reception of fatty matters 

 as a much more complex phenomenon, and 

 the result of what we may venture to call 

 more vital processes. For the way in which 

 ether and other solvents act upon the chyle 

 appears to prove, that the fatty contents of its 

 molecules are still oily ; and not saponified, 

 like such diffused fluids. And while the 

 position of the capillary plexus, and the rapid- 

 ity and quantity of its stream, render it pro- 

 bable that any merely diffusive action would 

 disproportionately affect the blood -which 

 by the way is often more alkaline than the chyle 

 -^-a chemical and physical comparison of these 

 two fluids would seem to show that the re- 

 verse is actually the case : tbat a larger quan- 

 tity of fat is taken up by the lacteals than by 

 the blood-vessels. This view is also con- 

 firmed by the results of violent inflamma- 

 tion*, or of great interference with the blood- 

 vessels j : changes, neither of which would 

 probably have much direct effect on the physical 

 action of an independent system of tubes, but 

 which are nevertheless alleged entirely to pre- 

 vent the formation of chyle. In any case, it 

 would seem that there are strict limits to the 

 quantity of fatty matter which can be absorbed. 

 Hence when the amount of fat present in any 

 particular region at all exceeds what its villi 

 can take up, it is passed on to other portions 

 of intestine ; failing absorption by which, it is 

 ultimately discharged unchanged in the faeces. 



Intestinal Follicles. ,J We pass on to the 

 description of a class of structures which are 

 essentially closed sacs; and which, represented 

 in the stomach by the lenticular glands, pervade 

 all the remainder of the intestinal canal under 

 the two forms of solitary and agminate fol- 

 licles : the latter being, as their name implies, 

 essentially clusters of the former. 



Agminate follicles. Of the very numer- 

 ous names which have been bestowed upon 



* French s, Loc. cit. 



t Fenwick in " Lancet " for 1845, p. 64. 



| The etymology of the word "follicle " quite 

 permits its application to these closed sacs : to which 

 indeed it seems desirable that we should restrict it^ 

 in speaking of the various constituents of the intes- 

 tinal mucous membrane. 



Until a more uniform nomenclature is adopted, 

 it seems advisable to enumerate a few of these 

 names. Such are the titles of glandulee Peyerianee ; 

 agmina Peyeri ; glandulee aggregates ; glandules, agmi- 

 nate ; vesicularum agmina ; plexus intestinaks ; plaques 

 gaufrees; and finally, Peyer's patches. The latter 

 uncouth designation is, perhaps, that most com- 

 monly made use of in this country. But as Peyer 

 appears to have been anticipated b}' our countryman 

 Grew in the discovery of these structures, there is 

 the less need of clinging to one of those unmeaning 



these follicles, that above made use of seems 

 preferable ; since it best connotes both 

 their structure and arrangement. There are 

 generally about twenty clusters of these 

 agminate follicles scattered throughout the 

 small intestine. Their shape is commonly 

 that of an oval, having a length about twice 

 its width. They are situated on the free 

 border of the bowel, or opposite to the 

 attachment of its mesentery ; and usually 

 correspond to about the lower three-fifths of 

 the small intestine, or to that part of it which 

 is regarded as the ileum. Hence they have 

 been looked upon as, in a certain sense, 

 characteristic of this region. But they some- 

 times extend into the jejunum, being scattered 

 sparingly throughout its lowest segments. 

 And they may rarely be found even in 

 the duodenum. In such cases, their entire 

 number is usually about twice or thrice that of 

 the average given above. 



But amid all their variations of number, 

 size, and extent, the agminate follicles seem 

 to retain a certain predominant relation to 

 the end of the ileum. For it is here that they 

 are both largest and most numerous. And 

 while in the remainder of the small intestine, 

 their length is usually rather under than over 

 an inch, nothing is more common than to find 

 the immediate neighbourhood of the ilio-caecal 

 valve occupied by a single irregular cluster ; 

 which has a length of two, three, or even four 

 inches, and a width which carries it round 

 ils or fths of the inner circumference of the 

 intestinal tube. 



Fig. 267. 



Agminate follicles as seen by reflected light. Magni- 

 fied 4 diameters. (After Kodliher.} 

 _ a, general mucous surface with villi ; b, depres- 

 sions leading to the several follicles; c, intervals 

 between them, covered by small villi. 



On examining the mucous membrane of the 



surnames, which every practical teacher of anatomy 

 will probably agree with the author in thinking 

 very objectionable. 



