MOUTH. 



[ 518 ] 



MUCEDINES. 



to 1-6" in size, and open by short excretory 

 ducts into the mouth. They consist of 

 glandular lobules enveloped in areolar tissue 

 with elastic fibres, the whole being sur- 

 rounded by a firmer portion or capsule, and 

 a branched duct. The lobules are composed 

 of a number of convoluted canals or lobular 



Fig. 493. 



k« ) 



>^ 



Human racemose mucous gland from the floor of the 

 cavity, of the mouth, a, areolar coat; 6, excretory duct ; 

 c, glandular cseca ; d, lobular ducts. 



Magnified 50 diameters. 



ducts, with simple or compound caeca or 

 glandular vesicles, each consisting of a 



Fig. 494. 

 a 



The ducts of the lobules have a coat of 

 connective tissue, with networks of fine 

 elastic fibres, and a single layer of cylindrical 

 epithelial cells. 



Fig. 49 



o. 



Diagram of two lobular duets of a mucous gland, a, common duct ; 

 6, lobular branch ; c, glandular vesicles in situ ; d, the same separated, 

 and the ducts unfolded. 



Magnified 100 diameters. 



basement membrane and a single layer of 

 angular epitheHal cells. The latter separate 

 very readily ; and then the caeca appear filled 

 with a granular mass. 



Two glandular vesicles of a human racemose mucous 

 gland, a, basement-membrane; b, epithelium, side 

 view ; c, the same in surface view. 



Magnified 100 diameters. 



The mucous liquid of the mouth con- 

 tains, in addition to detached epithelial 

 cells, very transparent corpuscles, about 

 1-2000 to 1-1500" in diameter, consisting 

 of a delicate cell-wall, a nucleus, with a 

 number of minute moving molecules. We 

 have figured these among the Test-Objects 

 (PI. 1. fig. 5). They are called mucous or 

 salivary corpuscles. KoUiker regards them 

 as a form of exudation corpuscles : and this 

 view is probably correct ; for they may occur 

 in the secretion of any mucous surface, and 

 have no special connexion ^^ ith the salivary 

 glands : we have found them in m3'riad3 

 in the urine. 



The secretion of the mouth frequently 

 contains very slender filaments of a fungus 

 (Leptothbix), with species oi Monas and 

 of Vibrio. 



BiBL. Kolliker, Mih. An. ii. ; 

 Sebastian, JRech. An. s. I. gland, 

 labial. ; Webb, Qu. Jn. Med. Sci. 

 1857; Ward, Todd's Ci/cl. An.&e. ; 

 Klein in St/'icker, Hist. i. 



MUCEDTNES.— A family of 

 Hyphomycetous Fungi, forming 

 moulds and mildews upon living 

 or decaying animal or vegetable 

 substances, and contributing to 

 their decomposition, character- 

 ized by a flocculent mycelium 

 bearing erect, continuous or sep- 

 tate, simple or branched, tubular 

 pellucid filaments, terminating 

 in single spores or strings of spores, which 

 soon separate from each other, and lie 

 among the filaments of the mycelium. 

 This tribe includes a number of the most 



