R. T. v Young 
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Literature. 
Calkins, G. X.. 1901. The Protozoa, New York. 
Child, C. M., 1904. On amitosis in Moniezia, in Anat. Anz., Vol. XXV, pp. 545 — 558. 
1907a. Studies on thc relation between amitosis and mitosis, in Biol. Bull., Vol. XII, 
pp. 89—114. 
- — - 1907b. Ibid. Vol. XII. pp. 175—224. 
1907c. Ibid. Vol. XIII, pp. 138—160. 
1907d. Ibid. Vol. XIII, pp. 165—184. 
1907e. Amitosis as a factor in normal and regulatory growtli, in Anat. Anz., 
Vol. XXX, pp. 271—297. 
Drzewecki, W., 1904. Über vegetative Vorgänge im Kern und Plasma der Gregarinen 
des Regenwurmhodens, in Arch. f. Protistenk., Vol. III, pp. 107 — 125. 
Young, R. T., 1908. The histogenesis of Cysticercus pisiformis, in Zool. Jalirb. (Anat. 
u. Ont.), Vol. XXVI, pp. 183—254. 
Explanation of Plates V and VI. 
Figs. 1, 2, 4, 5, 6, 7, 8, 9, 10. 12, 13, 14 x 650; Figs. 11, 17, 18x470; Fig. 3x1000; 
Figs. 15, 16 x 1000. 
Fig. 1. Sub-cuticula of Moniezia, showing atypical cells and developing nuclei. 
Fig. 2. Anlage of developing genital ducts of Moniezia, showing nuclear varia- 
tions. 
Fig. 3. Sub-cuticula of Thysanosoma. The small black dots are mainly food 
bodies, but in the center of the field is clearly shown a developing nucleus, with a di- 
stinct »nucleolus« and a very faint membrane surrounding about 1 / 2 of the nucleus. 
Fig. 4. Anlage of genital ducts of Thysanosoma. 
Fig. 5. Sub-cuticula of Taenia crassicollis, showing atypical cells. 
Fig. 6. Anlage of genital ducts of Taenia crassicollis , showing nuclear variations. 
Fig. 7. Sub-cuticula and parenchyma of Taenia serraia, showing staining dif- 
ference of different areas. 
Fig. 8. Sub-cuticula of Anoplocepliala, showing tvpical and atypical cells. 
Fig. 9. Sub-cuticula and parenchyma of Anoplocepliala, showing cytogenic 
masses with developing nuclei. In the large mass in center of field, five developing 
nuclei, represented by »nucleoli«, surrounded by narrow unstained areas, are seen. 
In the mass in lower right hand part of field, two nuclei, eacli with a large »nu- 
cleolus« surrounded by a lighter area, and with partly formed membranes are seen; 
while below this mass is seen a nucleus which has evidently just separated front the 
latter. In the mass below is shown a developing »nucleolus«, unsurrounded by the 
usual clear zone. 
Fig. 10. Anlage of genital ducts of Anoplocepliala, showing two mitoses. 
Fig. 11. Sub-cuticula and parenchyma of Crossobothrium. Many food bodies 
are here seen scattered thru the tissues. 
Fig. 12. Anlage of genital ducts of Crossobothrium, showing nuclear variations. 
