Faull. — Development of Ascus. 
EXPLANATION OF PLATES. 
All drawings were made with the aid of a camera lucida. Fig. 69-79 are 
from cover-glass preparations, the rest from sections. 
Fig. 1. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Fig. 13. 
Fig. 14. 
Fig. 15. 
Fig. 16. 
PLATE 7. 
Fig. 1-16, Hydnobolites sp. 
i 
Young uninucleated ascus. Differentiation of the contents into dense 
and vacuolated portions has already taken place. Very small 
extranuclear bodies lie just outside the nuclear wall. 
Oblique section of an older ascus. The dense protoplasm has 
become somewhat vacuolated. There are three large extranuclear 
bodies shown. 
Transverse section of upper part of a still older ascus. There are 
coarse fibrillar radiations out from the nucleus. The nucleus is 
surrounded by several small extranuclear bodies. 
Longitudinal section of a more advanced stage than in figure 3. 
Protoplasm finely reticular and delicately radiate about the nucleus. 
Extranuclear bodies scattered. 
Longitudinal section at time first aster appears. Extranuclear bodies 
occur at this stage near the periphery only. 
Equatorial-plate stage of first spindle. 
Same nucleus with spindle as in ligure 6. 
First mitosis. Daughter chromosomes are formed. 
Early anaphase stage of first mitosis. 
Spindle elongating in anaphase stage of first mitosis. Chromosomes 
have reached the poles. 
First mitosis. Nuclear wall has disappeared. Protoplasm more 
coarsely reticulated except in the immediate neighborhood of the 
nucleus. 
Same spindle as in-figure 11. 
End of first mitosis, showing extreme elongation of spindle and the 
vanishing nucleolus. 
One of the two daughter nuclei following first mitosis in resting 
condition. Single centrosome. The dense protoplasm is now 
uniformly and rather coarsely reticulated. 
Somewhat later stage than in figure 14. Protoplasm surrounding the 
nuclei begins to become finely reticulated and radiate. The fusion 
of vacuoles below is practically complete thus providing the dense 
protoplasm with a continuous plasma membrane. 
Two-spindle stage in longitudinal section of ascus. 
