518 ‘The Botanical Gazette. [December, 
On rat dung from Greenville, Ohio (W. H. Rush), para- 
sitic on Mucor. 
Harvard University. 
EXPLANATION oF PLATE XXXIV. 
Dispira Americana Thaxter. 
Fig. 1. Terminal portion of a small fertile hypha. 
Fig. 6. Optical section of a fertile head showing mature sterigmata 
tom which the spore chains are in process of budding. 
Fig. 7. The same with nearly mature spore chains. 
Fig. 8. Sterigma with two mature spore chains 27 situ. 
ig. 9. Two spores still adherent to one another. 3 
Fig. 10. Fertile hypha of Mucor mucedo attacked by parasitic branches 
ispira which are producing zygospores in various stages 
cf development. 
Fig. 11. The same showing younger parasitic branches and zygospores 
: more highly magnified. 
Fig. 12-13. Two mature zygospores. 
x —The original figures have been reduced by photo-lithography % 
and were drawn with the following approximate magnifications in diameters: 
Figs. I, 2, 10, X240. Figs. 3-9, X925. Figs. 11-13, 420. 
