G EX ERA L A NA TOM V. 



93 



grows as a cylindrical cord or tube from the surface down 



into the deeper layers of tissue; 



this cord of cells seldom remains 



simple; it usually branches and 



forms the compound glands, P 



which may consist of hundreds 



or thousands of glandular 



pouches, all emptying into a 



common duct. Among the 



multicellular glands are to be 



distinguished tubular and acin- 



ous forms. In the case of the 



tubular glands (Fig. 28) the 



simple or branched glandular 



pouches preserve the Same tubll- FIG. 27. Unicellular glands from edge 



. . , r . of the mantle of Helix pomatia. e, 



lar Calibre trom beginning tO epithelium; </, unicellular glands ; /, 



. . pigment cells. 



end ; in the acinons glands (r ig. 



29), on the contrary, the blind end of the glandular pouch 



widens into a swelling, which chiefly comprises the secre- 



FIG. 28. Tubular glands. (After Toldt.) A, glands of Lieberkiihn from the human intes- 

 tine ; A', of the conjunctiva of the eye; , of the cat's stomach; C, from the pyramids 

 of the dog's kidney; Z>, from the cortex of the rabbit's kidney. 



tory cells, and is related to the anterior part of the glandu- 

 lar pouch, the duct, as grapes are to their stem. To the 



