32 The Botanical Gazette. . [January. 
14. Schmitz, Ueber die Structur des Protoplasmas und der 
Zellkerne der Pflanzenzellen. Sitzungsb. d. niederrh. Ges. 
f. Natur- und Heilkunde zu Bonn 322. 1879. 
15. Sorauer, Pflanzenkrankheiten. 2: 3. 1886. 
16. Strasburger, Ueber Azolla. 1873. 
University of Illinots, Champaign. 
EXPLANATION OF PLates III anp IV. 
Prate III.—Fig. 1. Portion of cross section of Cycas revoluta tubercle re 
presenting — Someenagy 76 dermatogenic, subdermal parenchyma, palisade, 
d parenchyma layers. Nostoc im situ 
” Fig oe ap ed of longitudinal section of tubercle showing apical per with- 
out the root cap. Beginning of palisade layer with a few nostoc filaments. 
ig. 3. Diagramatic section of tubercle, — manner of branitirie and 
distribution of vascular a es. 
Fig. 4. Vo. commun. 
= Fig. e of the parenchyma = palisade cells highly mag- 
nified showing retic slated: structure of cytoplasm and nucleoplasm. Larget 
black dots in cells represent full grown fee Same or dermatosomes. Starch and 
aan 7.P Plasomes from palisade cells. 
Fig. 8. Bacteria from paren chyma and vascular tissue 
(Figs. 6, 7 and 8 very highly magnified.) 
