1034 Butler .— On Allomyces , a new Aquatic Fungus . 
Pringsheim, N. (’85) : Ueber Cellulinkorner. Ber. d. deut. bot. Gesellsch., i. 
Reinsch, P. F. (’78) : Beobachtungen iiber einige neue Saprolegnieae, &c. Pringsh. Jahrb., xi. 
Rothert, W. (’90) : Die Entwickelung der Sporangien bei den Saprolegnieen. Cohn’s Beitrage, v. 
Schroeter, J. (’92) : Phycomycetes, in Engler undPrantl: Die natiirl. Pflanzenfam., Teil I, Abt. i. 
Thaxter, R. (’95) : Gonapodya and Myrioblepharis. Bot. Gaz., xx. 
-(’96): Blastocladia. Bot. Gaz., xxi. 
-(’96): Rhipidium Sapromyces and Araiospora. Bot. Gaz., xxi. 
Vuillemin, P. (’07): Les bases actuelles de la systematique en Mycologie. Progressus Rei 
Bot., ii. 
EXPLANATION OF FIGURES 1-18. 
Illustrating Dr. Butler’s paper on Allomyces. 
Fig. i. Single plant showing basal body, rhizoids, and fertile branches which bear sporangia 
and a few resting spores. At a the lowest sporangium was formed after the upper was cut off and 
the axis had continued to grow from below it. 
Fig. 2. Much branched basal body; branching dichotomous. 
Fig. 3. Unbranched columnar basal body. 
Fig. 4. Sub-dichotomously branched fertile hypha. 
Fig. 5. Sympodial fertile hypha. 
Fig. 6. Cluster of sporangia at the end of a fertile hypha. 
Fig. 7. A chain of ripe sporangia with papillae formed, just before discharge. 
Fig. 8. A chain of irregularly shaped sporangia. 
Fig. 9. Sporangium discharging zoospores through three openings. 
Fig. 10. Zoospores. At the top five zoospores just after emergence, showing the elongated 
shape, hyaline cap, and single posterior cilium ; on the left amoeboid changes in shape of a single 
zoospore shortly after emergence, cilium not shown; at the bottom four zoospores in the final 
shape taken during the period of active swarming. 
Fig. 11. Zoospore germinating with a branched germ tube. 
Fig. 12. Resting spore in surface view. 
Fig. 13. Details of the wall of a resting spore which completely filled the terminal cell of the 
hypha. The outer thin wall is that of the hypha; next is the thick exospore with pits (?) seen in 
optical section as dark bands; inside the structureless endospore. 
Fig. 14. Surface view of the wall of the exospore showing the pits (?). 
Fig. 15. Two resting spores formed free within the terminal cell of the hypha; that on the 
right is being set free by the rupture of the hyphal wall. 
Fig. 16. Resting spore completely filling terminal cell, the wall of which cannot be made out 
except at the lower part of the spore. Optical section through middle of spore. 
Fig. 17. Details of septum formation. ( a ) Cellulin bodies collected at the origin of a lateral 
branch. (p) Same in surface view. ( c ) Peripheral interrupted plate in surface and profile view. 
(1 d ) A septum of the basal body completed, with cellulin bodies grouped above and below. 
( e) Mature septa, upper unusually thickened, lower of the type ordinarily found in the fertile 
hyphae. 
Fig. 18. Structure of protoplasm of a fertile hypha; lower portion reticulate, upper finely 
granular. 
