228 \V I \TERTON C. CURTIS. 



PLATE VII. 



Figures showing miscellaneous points in the proglottid formation of C. laciniatiun. 

 All from camera lucida drawings. The magnification is given for the figures as repro- 

 duced. 



FIG. 21. A specimen which has just entered the "long-necked" condition. 

 There are 34 old proglottids. Reproductive organs probably occur in front of the 

 seventeenth proglottid, but as the specimen was stained for another purpose this 

 cannot be determined with certainty. X I2 diameters. 



FIG. 22. A "long-necked" specimen with a single one of the old "anterior" 

 proglottids attached and segmentation beginning in the posterior part of neck region. 

 X 12 diameters. 



FIG. 23. Part of a young specimen showing a short non-segmented zone with an 

 abrupt transition of the "anterior" proglottids into the zone. There were in this 

 instance 30 "anterior" and upwards of 217 "posterior" proglottids. X 5 diameters. 



FIG. 24. A "long-necked" specimen with a single "anterior" proglottid of the 

 earlier chain still attached at the posterior end and the new segmentation well begun 

 at either end of the neck region. < 12 diameters. 



FIG. 25, a, b and f. To show the characteristic shapes of the "anterior" (a) and 

 the "posterior" proglottids (<:). Also the unsegmented zone which separates them. 

 All from the same specimen. There were 35 anterior and 250 -)- posterior segments. 

 < 50 diameters. 



FIG. 26. Part of a transverse section through the non-segmented zone of a speci- 

 men about the stage of Fig. 7, PL I. See discussion on page 216 of the text. 



