29O ELEMENTARY BIOLOGY. [CHAP. 



In the vicinity of the base of this gland, the 

 genital organs come into close apposition with the 

 intestine and aortic vessels. Carefully liberate 

 them en masse from their surroundings and pin 

 down under water — the albumen gland with its 

 flattened face uppermost. Now follow in order — 



b. The further course of the hermaphrodite duct. On 

 reaching the albumen gland it becomes suddenly 

 constricted, to form an exceedingly delicate thread- 

 like tube. As this is usually of a dead-white colour 

 it can be seen through the more transparent albu- 

 men gland, in the superficial portion of which it lies 

 buried. It passes for a short distance towards the 

 apex of this gland, and then, turning sharply upon 

 itself, is continued straight back towards the base 

 of the same ; it here becomes suddenly enlarged 

 to form a convoluted duct with sacculated walls, 

 which is continued on towards the genital orifice. 



The transition between the two segments of the 

 hemaphrodite duct here described, is so sudden as 

 to make it appear that they are distinct structures ; 

 hence it is that the sacculated segment is sometimes 

 spoken of as an oviduct. 



c. Its walls are beset externally by a continuously 

 straight series of glandular follicles, making up an 

 accessory gland (so-called prostate). 



d. Open up the albumen gland and note its spacious 

 central duct. It will be found to enter the enlarged 

 "head" of the sacculated portion of the hermaphro- 

 dite duct. Follow the hermaphrodite duct onwards 

 — its sacculations gradually disappear, and it 

 suddenly divides into two — oviduct and vas deferens. 



