CEREUS. 



[ 128 J CERUMINOUS GLANDS. 



Char. Body rounded or discoidal, tuber- 

 culated, with a variable posterior prolonga- 

 tion in the form of a tail, which is longer or 

 shorter and more or less filiform. 



Dujardin remarks that the only absolute 

 difference between the Cercomonads and the 

 Monads consists in the presence of the posterior 

 prolongation, which is formed by the substance 

 of the body becoming agglutinated to the 

 slide, and more or less drawn out so as to form 

 sometimes merely a tubercle, at others an 

 elongated tail, or a filament 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. After this, 

 we may pass over the nine species. 



BiBL. Duj. Infus. p. 287. 



CEREUS. See Cactace^. 



CERUMEN.— The so-called 

 *wax' of the ear. 



Its morphological elements 

 are, — 1. Hairs; these exhibit very 

 beautifully the external layer of 

 epidermal scales. 2. Occasion- 

 ally, the Demodex foUiculorum. 

 3. Numerous epidermal scales, 

 mostly compressed, shrunk, or so 

 altered as to resemble fibres, but 

 resolvable into their original form 

 by warming with solution of pot- 

 ash and the subsequent addition 

 of water ; by this treatment they 

 are frequently rendered brown, 

 purplish, or almost black. 4. 

 Very numerous cells, filled with 

 pale fatty matter, of a rounded 

 or elongate, flattened, or irregu- 

 lar form ; these are derived from 

 the sebaceous follicles. 5. Nu- 

 merous free oil-globules of the 

 most varied sizes. 6. Yellow or 

 brown granules, and aggrega- 

 tions of them, mostly free, some- 

 times contained in cells. 7- Va- 

 rious elements derived from with- 

 out, as fibres of cotton, linen, 

 &c. See Ceruminous Glands, 

 and Chemistry. 



CERUMINOUS GLANDS. 

 — The glands which secrete the 

 'wax' of the ear. They are si- 

 tuated in the tube of the ear, or 

 the meatus auditorius externus 

 of anatomists. They closely re- 

 semble the sudoriparous ducts in 

 appearance, and exist only in 

 the cartilaginous portion of the 



passage, where they are situated between 

 the skin and the cartilage, or the fibrous 

 mass which occupies its place. Each con- 

 sists of a simple tube coiled at one end, so 

 as to form a gland (fig. 119 d), the other 

 being continued in the form of a duct 

 (fig. 119 e) to the surface of the skin, upon 

 which it opens ; occasionally, however, into 

 the upper part of the hair-follicle. 



The glands consist of an external coat of 

 areolar tissue, with scattered, somewhat 

 spindle-shaped nuclei, and very fine nuclear 

 fibres ; a layer of smooth, longitudinal, mus- 

 cular fibres, consisting of short fibre-cells 

 with elongated nuclei; and an inner single 

 laver of epithelium, composed of polygonal 

 cells, from 1-1800 to 1-1100" in diameter, 

 with roundish nuclei. These cells contain 

 round or irregularly-shaped yellowish-brown 



Fig. 119. 



]\Iagnified 20 diameters. 



Perpendicular section of the meatus auditorius externus, a. Coriuni ; 

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

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

 tissue. 



