THE ANATOMY. SPERMIDUCAL GLANDS 



107 



the origin of this body is an outgrowth of the lining epithelium of the atrium ; it is 

 a curious fact that the covering of peritoneum upon the atrium ceases at the point 

 where the ' prostate ' is attached, a fact which, if the development of those parts was 

 not known, might give rise to the idea that the 'prostate' was nothing more nor 

 less than a tract of peritoneum modified to serve a special function. NASSE speaks 



Fig. 28. 



ILYODRILUS COCCINEUS. 



MALE EFFERENT APPARATUS. 



(After Stole.) 



i. Funnel. 2. Sperm-duct. 3. Penis. 

 4 Muscles for its retraction. 5. 



Glandular covering of 6. ' Atrium.' 



Fig. 29. 



BOTHRIONEURON VE.TDOVSKYANUM 

 MALE EFFERENT APPARATUS. 



(After Stole.) 



i. Proximal region of ' atrium.' 2 ' Para- 

 trium.' 3 Distal region of ' atrium.' 4. Penial 

 setae. 5. External pore. 6. Muscles for pro- 

 trusion of distal end of efferent apparatus. 

 -. Muscle attached to sperm-duct (8). 9. Funnel. 



of a fine lumen to each group of cells in the prostate ; but it is fairly clear that 

 the gland is solid ; the cells of which it is composed appear to correspond with 

 other unicellular glands found so commonly among earthworms; for example, the 

 capsulogenous glands of the Perichaetidae ; the ' atrium ' being developmentally 

 an involution from the outer layer of the body it is not remarkable to find 



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