352 Wisconsin Academy of Sciences, Arts, and Letters. 
do not germinate at once to form conidia, bnt one or two may 
lag behind and show no indication of germinating even after some 
of the others have produced secondary conidia (fig. 38). 
The secondary conidia are very small, and it is these small conidia 
that produce the vegetative mycelium. The attempt to grow 
mycelium on artificial media was not successful. Short hyphae 
were produced but soon died. These hyphae were slender, having 
a diameter less than the diameter of the conidium and containing 
a very vacuolate cytoplasm (fig. 39). 
Summary 
1. TapJirina coryli Nishida is an intercellular parasite infecting 
all parts of the leaves and the cortex of the one-year-old twigs of 
Corylus americana. 
2. The vegetative cells form long filaments and frequently 
branch dichotomously. They serve to distribute the fungus 
through the leaf and through the twig. 
3. The binucleate condition arises in the vegetative cells, and 
not in the ascogenous cells. 
4. The division of the vegetative nucleus is mitotic, with small 
spindles and centrosomes. It is difficult to recognize individual 
chromosomes in the chromatin masses. 
5. The binucleate condition continues into the ascogenous cells, 
and then nuclear fusion takes place. Nuclear fusion takes place 
most frequently early in the morning. 
6. The fusion nucleus is a typical resting nucleus, containing 
a large nucleole, chromatin on a linin network, and a central mass 
of deeply staining chromatin. 
7. The division of the fusion nucleus is a heterotypic reduction 
division, as is indicated by the occurrence of synapsis and of a 
later stage showing the spirem thrown into a definite, looplike ar¬ 
rangement from the center to the periphery. 
8. Granular bodies are present at the ends of the spindle and a 
clear area surrounds the entire spindle. It is not definite how 
these granular bodies are formed. 
9. The separation of the basal cell from the ascus proper takes 
place by the constriction of the plasma membrane. 
10. One nucleus is left in the basal cell; the sister nucleus 
passes into the ascus proper. Gradually the former nucleus dis¬ 
integrates, but the second and its derivatives divide to form nuclei 
for the eight primary spores. 
