CERCOMONAS. 



[ 154 ] CERUMINOUS GLANDS. 



almost as slender as the anterior filament 

 and susceptible of an oscillating motion; 

 also that he thinks he has frequently seen 

 Monads gradually pass into the state of 

 Cercomonads. See BODO. 



Found in infusions, pool-waters, c. 



C. acuminata (PI. 30. fig. 22). C. crassi- 

 cauda (PI. 30. fig. 23). C. intestmalis, in 

 typhoid diarrhoea, cholera; other species, 

 many doubtful. 



Dallinger and Drysdale describe in a 

 species of Cercomonas (C. typicus, Kent), 

 found in cod-macerations 2-3 months old, re- 

 production by transverse fission ; also by con- 

 jugation the individuals becoming amoe- 

 boid, fusing together, and forming a smooth 

 cyst, from which myriads of almost imper- 

 ceptible germs are subsequently liberated. 



BIBL. Duj. Infos. 287; Pritchard, Inf. 



Fig. 115. 



Magnified 20 diameters. 



Perpendicular section of the meatus auditorius externus. a. Cerium; 

 b, rete mucosum ; c, epidermis ; d, ceruminous glands ; e, their ducts ; 

 /, their terminal orifices; g, hair- follicle ; h, sebaceous follicles; i, fatty 

 tissue. 



497 ; Perty, Z. KennL 171 ; Kent, Inf. 2o8 ; 

 Dallinger and Diysdale, M. M. Jn. 1873, 

 x. 53, 245. 



CEREUS. See CACTACEJE. 

 CERU'MEN. The so-called 'wax' of 

 the ear. 



Its morphological elements are : 1. Hairs ; 

 these exhibit very beautifully the external 

 layer of epidermic scales. 2. Occasionally, 

 the Demodex folliculorum. 3. Numerous 

 epidermic scales, mostly compressed, shrunk, 

 or so altered as to resemble fibres, but re- 

 solvable into their original form by warm- 

 ing with solution of potash and the subse- 

 quent addition of water; by this treat- 

 ment they are frequently rendered brown, 

 purplish, or almost black. 4. Very nu- 

 merous cells, filled with pale fatty matter, 

 of a rounded or elongate, flattened, or irre- 

 gular form ; these are derived 

 from the sebaceous follicles. 

 5. Numerous free oil-globules 

 of the most varied sizes. 6. 

 Yellow or brown granules, 

 and aggregations of them, 

 mostly free, sometimes con- 

 tained in cells. 7. Various 

 elements derived from with- 

 out, as fibres of cotton, linen, 

 &c. The deafness of old per- 

 sons usually arises from an 

 accumulation of indurated 

 cerumen. See CEBUMINOUS 

 GLANDS. 



CERU'MINOUS GLANDS. 

 The glands which secrete 

 the ' wax ' of the ear. They 

 are situated in the tube of 

 the ear, or the meatus audi- 

 torius externus of anatomists. 

 They closely resemble the su- 

 doriparous ducts in appear- 

 ance, and exist only in the 

 cartilaginous portion of the 

 passage, where they are situ- 

 ated between the skin and the 

 cartilage, or the fibrous mass 

 which occupies its place. 

 Each consists of a simple 

 tube coiled at one end, so as 

 to form a gland (fig. 115 ef), 

 the other being continued in 

 the form of a duct (fig. 115 e) 

 to the surface of the skin, 

 upon which it opens; occa- 

 sionally, however, into the 

 upper part of the hair-follicle. 

 The glands consist of an ex- 



