GLAND TISSUE. 



135 



each other in the gastric-mucous membrane, the individual 

 tubes occupy about the position of the transversely- 

 striated muscular filament (Fig. 

 91). The reticulum (Fig. 126) 

 becomes similarly elongated ; 

 only the rings around the 

 gland apertures, together with 

 anomalous arterial and venous 

 branches, produce a considera- 

 ble difference in the thing. 



Turning 



to 



Fig. 126 — The vascular r.et-work of the mu- 

 cous membrane of the human stomach— semi- 

 di.uramatic. The (finer) arterial trunk di- 

 vides into the elongated, capillary net-work, 

 which passes over into the rounded reticulum 

 of the gland apertures, from which the vein 

 (the wider, darker vessel J arises. 



the racemose 

 glands, with the generally 

 rounded form of the element, 

 the small acinus, the capillary 

 net-work must, as we have 

 already remarked, correspond 

 to the form of a fat lobule (Fig. 

 93). Our Fig. 127 represents 

 the capillary arrangement of a 

 larger lobular group of the 

 pancreas. The figure might, 

 with equal propriety, be used 

 for the vascular arrangement 

 of a conglomeration of the lobules of fat cells. 



The immense assimilation of glandular organs renders a 

 considerable wealth of lymphatic passages, which are to re- 

 store the superfluous transudation to the blood passage, very 

 appreciable. A portion of these lymphatic passages have 

 been discovered very recently. Smooth muscular fibres, 

 which either invest the gland body or occur in the parieties 

 of the excretory ducts, scarcely require a further physiologi- 

 cal explanation. They are of great importance for the ex- 

 pulsion ot the secretion. 



Concerning the gland nerves, this most obscure portion of 

 the structure of the organ in question, we shall speak later. 



The last which remains for discussion is the excretory duct. 

 If we take a simple gland tube (Fig. 128), such as are con- 



