A Study of the follicular Epitheliom from the Ovary etc. 641 
and their nuclei change their position; at first they lie with the long 
axis along the surface of the oöcyte, the nuclei become spherical and 
then the long axis, both of cell and nucleus, assumes a radial posi- 
tion. Düring this change the epithelial cells grow and increase in 
number by mitosis. 
Very soon after the chambers are formed the secretory activity 
of the epithelial cells begins; this is sliown in different ways. At 
about the time the maximum size of the oöcytes is reached the epi- 
thelial cells again change their shape; they at first widen, decreasing 
in length. This continues until the long axis of the cells finally again 
changes to occupy the same position relative to the oöcyte which it 
had at first in the youngest chambers. The nuclei after they have 
shortened a little, become constricted at one or more places; they 
then begin to bend and become very irregulär in shape. 
In the walking-stick nearly all the apparent cases of amitosis in 
the epithelium of the old chambers are really due to this bending of 
the nucleus and the parts which at first appear to have separated 
from each other are, in reality, nearly always connected by thin 
Strands. 
Zoological Laboratory, University of Wisconsin, Madison, Wis. 
Bibliography. 
1. Berlese, A. Fenomeni che accompagnano la fecondazione in taluni insetti. 
Rivista di Patologia Vegetale. Vo! VII. 1898. 
2. Brandt, A. Über die Eiröhren der Blatta (Periplaneta) orientalis. Mem. 
l'acad. Sc. St. Petersbg. Vol XXI. 1874. 
3. Über das Ei und seine Bildungsstätte. Leipzig. 1878. 
4. Die Ernährung und das Wachstum des Dotters im Insektenei. Zool. 
Anz. Bd, VIII. 1885. 
5. De Bruyne, C. Recherches au sujet de l’intervention de la Phagocytose 
dans le developpement des Invertebres. Archive de Biologie. Vol. XV. 
1898. 
6. Daiber, Marie. Beiträge zur Kenntnis der Ovarien von Bacillus rossii, 
nebst einigen biologischen Bemerkungen. Jen. Zeitschr. Natwissensch. 
Bd. XXXIX. 1905. 
7. Giardinia, A. Süll’ esistenza di una zona plasmatica perinncleare nel oocite. 
Pubbl. del Lab. Zool. e Anat. comp. Palermo. 1904. 
8. Gross, J. Untersuchungen über das Ovarium der Hemipteren, zugleich ein 
Beitrag zur Amitosenfrage. Zeitschr. wiss. Zool. Bd. LXIX. 1900. 
9. Untersuchungen über die Histologie des Insektovariums. Zool. Jahrb. 
Anat. Bd. XVIII. 1903. 
