GLAND TISSUE. 



131 



Fig. 120. — Human racemose pala- 

 tine glands. 



formed. It may acquire an excretory duct, and then the race- 

 mose gland, in its smallest and most simple form, is complete. 

 But these most elementary structures 

 are rare. As a rule (Fig. 120), several 

 acini form the still small gland body. 

 In larger and large organs the num- 

 ber of the gland lobules becomes 

 very great. 



It is scarcely necessary to remark 

 that transitions occur between the 

 tubular and racemose glands. 



3. Finally, we have another gland 

 with closed rounded gland capsules, 

 which latter are contained in abun- 

 dant connective tissue. This is the ovary. These rounded 

 .structures, which are constituted by a connective-tissue wall, 

 are called the Graafian follicles. Among the cells it con- 

 tains, one is noted for its size. This is the ovum (Fig. 5). 



That the latter becomes free by the rupture of the follicular 

 wall, we have mentioned above. Let us also add that the 

 ruptured follicle is incapable of further repair, but rather goes 

 to ruin by a process of cicatrization. The conditions are, 

 therefore, in contradistinction to those presented by other 

 glands, peculiar and anomalous enough. a 



The second and much more important constituent of our 

 organ is presented by the gland cells. We shall subsequently 

 see that they are nearly all derivatives of Remak's corneous 

 and intestinal-gland layer. Even in subsequent life, this epi- 

 thelial character is not renounced. 



The inner surfaces of the membrana propria are thus lined, 

 sometimes simply, sometimes in strata. In the excretory 

 portion of the gland, an ordinary epithelium subsequently 

 makes its appearance. The gland cell may be called a micro- 

 scopically small chemical laboratory. With its body it forms 

 the secretion, or changes the formative material received 

 from the blood into the latter. 



For this purpose our cells require 



a certain magnitude. 



