650 



MANUAL OF HISTOLOGY. 



Fig. 602. Trachoma gland from the ox, with injected 

 lymphatic canals: vertical section, a, submucous 

 lymphatic vessel ; c, splitting up of the same round 

 the follicle, ft. 



concentric layers of connective-tissue, and containing cells and a granular 

 matter. They have been named by histologists, after their discoverer, 

 the glands of Manz. 



In addition to these secreting organs of the conjunctiva we meet with 



lymphoid follicles, or, as they 

 have been named by ffenle, 

 trachoma glands (fig. 602). They 

 are to be found in man, in nume- 

 rous mammals, and in several 

 birds. They usually occupy, 

 but not in all animals, the inner 

 angle of the eye, especially in 

 the transition fold of the under 

 and third lid, or plica semi- 

 lunaris, and are sometimes scat- 

 tered, sometimes aggregated. 

 An enormous collection of 

 them, strongly resembling one 

 of Peyer's patches, may be ob- 

 served in the under eyelid of the ox (plaque of Bruch). In the human 

 conjunctiva they a're only met with irregularly and sparsely scattered. 



The structure of these bodies is that of 

 other lymphoid follicles (fret/, Hugue- 

 nin). Their vascular network is thin and 

 irregular ( 227). Around them, even with- 

 out injection, lymphoid lacunae may be 

 recognised. 



As regards the blood-vessels of the con- 

 junctiva bulbi, we find its capillary supply 

 derived from branches of the palpebral and 

 lachrymal arteries, as well as twigs given 

 off from the anterior ciliary vessels (comp. 

 312). The capillary system of the pal- 

 pebral conjunctiva is much more dense 

 and more extensive. 



The lymphatics of the conjunctiva were 

 discovered many years ago by Arnold, and 

 have been since observed by Teichmann. 

 A delicate zone of the same, about 0*9 

 mm. broad, encircles the cornea, and is con- 

 tinuous peripherally with the network of 

 wider canals of the sclerotic conjunctiva. 



The trachoma glands are likewise rich in 

 lymphatic vessels, as may be learned from 

 injection (Frey). 



In Bruchs plaque in the ox (fig. 602) 

 knotted lymphatics of considerable size, 

 ranging from 0*377 to 0-1511 mm., may 

 be observed traversing the submucosa 

 obliquely or perpendicularly (a). These form, at the under surface of 

 the follicle, a very complicated network of canals -0744-0' 11 28 mm. 

 in breadth, and give off other finer vessels, - 02 mm., which are also 

 arranged in a retiform manner, ascending through the narrow-meshed 



Fig. 603. Termination of the nerves of 

 the conjunctiva in end-bulbs. 1. From 

 the calf. 2. From man. 



