Frederic T. Lewis and Fred W. Thyng 517 
Stohr“ has found in the small intestine of guinea-pigs eight days old, 
“primary submucous glands” which penetrate the muscularis mucosae 
and expand in the submucosa. They are surrounded by ordinary con- 
nective tissue. In older guinea-pigs all such glands are in relation with 
lymph nodules. At the beginning of the colon there is a lymphoid struc- 
ture called the “tonsilla colica.” Here the primary submucous glands 
give off secondary buds from their expanded basal portion as described by 
Stohr in guinea-pigs, and also by Czermack, who notes that the lateral 
secondary pockets are rudimentary in the rabbit. 
Whether the lymphoid cells which invest these pockets arise from the 
epithelium, as believed by Retterer, von Davidoff, and others, or from 
the surrounding tissue, as described by Stohr, Czermack, and others, need 
not be discussed here. It is agreed that the lymphoid cells appear, and 
that the pockets become relatively small. The round lumen may give 
place to a cleft parallel with the intestinal surface, as figured by von 
Davidoff“ from a section of the vermiform process of an adult guinea- 
pig. Czermack™ states that the epithelium may be partly transformed 
into bodies comparable with the thymic corpuscles. 
In the pig there are lymph nodules on the valve of the colon which 
Klein” describes as follows: 
Each of the nodules surrounds a group of Lieberkiihn’s erypts which— 
different from the ordinary type—extend with their fundus through the 
muscularis mucosae into the submucous tissue. This group of Lieberkthn’s 
crypts generally opens through a longer or shorter common duct on the 
surface. The most typical arrangement is this: a group of 10 to 20 small 
Lieberktihn’s crypts situated in the submucous tissues and surrounded by 
a lymph follicle opens into a common cavity from which a duct passes 
through the muscularis mucose to the free surface. I have referred to 
these glands as “ flask-shaped glands.” 
The extension of intestinal glands (crypts of Lieberkiihn) through the 
muscularis mucosae in relation with a lymph nodule is a common occur- 
Stohr, P. Ueber die Entwicklung der Darmlymphknotchen und tiber die 
Riickbildung von Darmdriisen. Arch. f. mikr. Anat., 1898, Vol. 51, p. 1-55. 
“von Davidoff. Untersuchungen tiber die Beziehungen des Darmepithels 
zum lymphoiden Gewebe. Arch. f. mikr. Anat., 1887, Vol. 29, p. 495. 
%Czermack, N. EHinige Ergebnisse tiber die Entwicklung, Zusammenset- 
zung und Function der Lymphknotchen der Darmwand. Arch. f. mikr. Anat., 
1893, Vol. 42, p. 581-632. 
” Klein, E. Report on infectious pneumo-enteritis of the pig. 7th Ann. 
Rep. of the Local Government Board. Supplement for 1877, appendix B. 
London, 1878, p. 169-280. 
