1915] SchumacJicr: On Blcpharocorijs ct[ui sp. iiov 101 



The macronucleiis (mac. pi. 13. fig. 2) is .situated in the anterior 

 one-half of the body, dorsal and to the right of the oesophagus. In 

 general the raaeronuelens has a rather constant size, .shape, and position 

 in the animal. In side view (pi. 13, fig. 1 ) it is heart-shaped, with 

 the point extending posteriorly. Seen in a dorsal or ventral view 

 {mac, pi. 13, figs. 2, 4), its shape is more irregular, and it appears 

 blunt and rounded on both end.s. Its diameter remains fairly constant 

 until just posterior to the micronucleus. where it is greater. On its 

 dorsal surface near the right anterior side there is a small invagination 

 in which the micronucleus partly lies, and, as mentioned above, in its 

 left side there is a pronounced groove, along which the right wall of the 

 oesophagus runs. The macronucleus is distinctly granular. After 

 iron-alum haematoxylin stain these granules stand out very distinctly 

 and clearly, but owing to the thickness of the nucleus it was impossible 

 to count them in toto preparations. 



Measurements of several macronuclei vield the foUowiuff figures : 



isured L. 



1 14 



10 8 8 



16 9 9 



12 10 10 



14 9 11 



Average, 13 9 6 



L. — Greatest length in microns. 

 W. — Greatest width in microns, 

 r. — Greatest thickness in microns. 



The micronucleus (niic, pi. 13, figs. 2, 5) may be clearly distin- 

 guished even in the living non-stained animals. Here it appears by 

 transmitted light as a shining little body .situated in a depression of 

 the right dorsal .surface of the macronucleus, close to its anterior end. 

 It appears finely granular in structure and refracts light more strongly 

 than does the macronucleus. In the .stained material it is seen to be 

 an ellipsoidal structure, finely granular, staining deeply, and separated 

 from the macronucleus by a clear space. 



The single contractile vacuole (c. v., pi. 13, figs. 3, 4, 5) is situated 

 in the po.sterior ventral part of the body in very close relation to the 

 anal tube. It frequently reaches the size of a sphere with a diameter 

 equal to one-half a transdiameter of the whole body. 



