﻿ILLUSTRATIONS. 



[Fig. 1 is from unstained material. All other material was stained with acid carmine, 

 picric acid being used in some cases for counterstaining. Sections vary from 25 to 

 250 « in thickness. The magnification was governed with the view of bringing out 

 as well as possible the desired structures, rather than by the consideration of 

 uniformity.] 



Plate I. 



Fig. 1. Portion of strobila. Natural size. 



2. Section of head through two suckers and border of neural cavity. 1X75. 



3. Section of head in different plane, showing ( ?) neural cavity and ganglion. 



retracted rostellum and traces of excretory canals.- 1X75. 



4. Longitudinal section through neck, showing beginning of segmentation. 



1X30. 



Plate II. 



Fig. 5. Longitudinal sections of segments 372, 373 just internal to ventral excre- 

 tory canal, showing spiral course of dorsal canal. 1X80. 



6. Segments 375 to 397, showing the early appearance of the uterus and 



genital pore. 1X10. 



7. Saggital sections of segments 398 to 403, showing in different planes the 



early appearance of genital organs. 1 X 12. 



Plate III. 



Fig. 8. Saggital sections of segments 451 to 455, showing sexual organs about 

 mature. 1X12. 

 9. The same, highly magnified to show the form of uterus in a single segment. 

 1X98. 



10. Transverse section of segment, showing the coils of vagina between cloaca 



and ventral canal. 1X80. 



11. Saggital section of a younger segment showing the same. 1X82. 



12. Transverse section of segment showing genital pore, cirrus, and loop of 



vas deferens in cirrus pouch. 1X90. 



Plate IV. 



Fig. 13. Saggital sections of segments 493 to 495 in slightly different planes, 

 showing posterior dilations of the uterus and its anterior coils which 

 have nearly reached their maximum expansion before dividing. The 

 heavily stained vitellogen gland extending along the transverse canal, 

 and the more lightly stained ovarian lobes lying closely anterior to 

 it are at their greatest development. 1X20. 

 14. Saggital section of segment, in a ventral plane, highly magnified to show 

 inner length of vagina as it enters globular chamber from which 

 the ovospermatic duct proceeds posteriorly toward the vitellogen gland 

 and turns dorsally toward the shell gland which lies in a deeper plane. 

 1X40. 



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