COMPOUND SECEETING GLANDS. 



235 



Ihese into larger again, till they eventually terminate in one or more 

 principal excretory ducts (in), by which the secretion is poured out of 



Fig. 162. 



Fig. 162.— Plans op Extension of Secreting Membrane, by Inversion or Recession. 



A, simple glands, viz., r/, straight tube ; h, sac ; i, coiled tube. B, multilocular crypts ; 

 i, of tubular form ; I, saccular. C, racemose, or saccular compound gland ; in, entire 

 gland, showing branched duct and lobular structure ; n, a lobule, detached with o, branch 

 of duct proceeding from it. D, compound tubular gland. 



the gland. It is from the clustered arrangement of their ultimate 

 vesicular recesses that these glands are named " racemose" (in German 

 " traubenf(irmige Drlisen ") ; and they, for the most part, have a dis- 

 tinctly lobular structure. The lobules are held together by the branches 

 of the duct to which they are appended, and by interlobular connective 

 tissue which also supports the blood-vessels in their ramifications. The 

 larger lobules are made up of smaller ones, these of still smaller, and 

 so on for several successions. The smallest lobules (n) consist of two 

 or three groups of saccules, with a like number of ducts, joining into 

 an immediately larger ramuscule (o), which issues from the lobule ; and 



