CELL-DIVISION IN THE SEX CELLS OF TAENIA 225 
SUMMARY 
In conclusion, the evidence presented in these observations 
show that: 
1. Neither the character of cell-division nor the apparent 
frequency of cell-division is influenced by the time of the year, 
the time of the day, the amount of food material, or the use of 
chloroform. 
2. Under the conditions of my experiment the ova do not 
segment outside the body of the host. 
3. Division in the spermatogonial cells is unquestionably mi- 
totic. I find no condition that might be interpreted as amitotic 
division. 
_4, The spermatocyte divisions are mitotic. 
5. The second spermatocyte division follows the first without 
an intervening resting stage. 
6. In oogonial divisions mitosis is very frequent and there is 
no evidence of amitosis. 
7. The maturation of the ovum takes place by mitotic division. 
8. Mitotic division occurs both in late and early cleavages. 
9. In the cleavages nuclear division takes place very much in 
advance of cytoplasmic division which results in a syncytial 
condition of the ovum. 
10. The mitotic figure in the cleavages may lie in any position 
with reference to the periphery of the ovum and to the other 
nuclei of the ovum. 
11. The cleavage spindle may be long or short and the recon- 
struction of the nucleus may begin when the chromatin is some 
distance from the poles of the spindle. 
12. By the time reconstruction is completed the daughter 
nuclei become very large and consequently may lie in close 
contact. 
13. The close contact of nuclei is no indication of the char- 
acter of the cell-division. 
14. In Taenia teniaeformis I have found no condition that 
¢annot be as readily explained as the result of mitotic division 
as of amitotic division. 
