396 DALTON G. PAXMAN. 



(a) The chromidia, or diffused nucleus. 



(&) The irregular chromatin granules formed by the union of 

 numerous chromidia and surrounded by a clear zone. 



(c) The nuclear membranes of the nuclei in the masses vary 

 considerably from delicate, scarcely discernible membranes to 

 heavy, well developed ones. 



D. These masses appear to arise by the simultaneous growth 

 of cytoplasm and chromidial extrusions from the nuclei of certain 

 cells. 



3. The degenerate character of the nucleus is perhaps the result 

 of the parasitic habit of the cestode. 



I wish here to express my sincere thanks to Dr. R. T. Young, 

 whose valuable criticisms and suggestions made this work 

 possible. I also wish to express my indebtedness to Dr. B. H. 

 Ransom for identifying my material. 



LITERATURE. 

 Child, C. M. 



'<>7a Studies on the Relation Between Amitosis and Mitosis. BIOL. BULL., 



Vol. XII., pp. 89-114. 

 'o7b Ibid., Vol. XII., pp. 175-224. 

 '070 Ibid., Vol. XIII., pp. 138-160. 

 'O7d Ibid.. Vol. XIII., pp. 165-184. 

 '10 Ibid., Vol. XVIII. , pp. 109-119. 

 '01 Ibid., Vol. XXI., pp. 280-296. 

 Harman, Mary T. 



'13 Method of Cell-Division in the Sex Cells of Taenia teniseformis. Journ. 



Morphol., Vol. XXIV., pp. 205-242. 

 Richards, A. 



'n The Method of Cell Division in the Development of the Female Sex Organs, 



of Moniezia. BIOL. BULL., Vol. XX., pp. 123-179. 

 Young, R. T. 



'08 The Histogenesis of Cysticercus pisiformis. Zool. Jahrb. (Anat. und 



Ont.), Vol. XXVI., pp. 183-254. 

 '10 The Somatic Nuclei of Certain Cestodes. Archiv. fur Zellforschung, pp. 



140-164. 



'13 The Histogenesis of the Reproductive Organs of Taenia pisiformis. Zool. 

 Jahrb. (Anat. und Ont.), Vol. XXXV., pp. 355-419. 



