12 CONNECTICUT GEOL. AND NAT. HIST. suRVEY. [Bull. 
in manure, and so fresh manure applied to corn land is apt to 
increase the amount of smut. With onion smut we have a 
case where the seedlings while coming through the soil are in- 
fected by the smut established there through a previous 
smutted crop. . Onions raised from sets in this land are little. 
infected. Some success has been had in preventing this smut 
by treating the soil with a mixture of lime and sulphur, drilled 
into it at time of seeding. 
SYSTEMATIC TREATMENT OF CONNECTICUT 
SPECIES. 
The order Ustilaginee is divided into two families, based 
chiefly on the method of spore germination. They are the 
Ustilaginacee (represented in this state by the genera Cintrac- 
tia, Schizonella, Sorosporium, Sphacelotheca, Tolyposporium, 
Ustilago), and the Tilletiacee (represented by Doassansia, 
Entyloma, Neovossia, Tilletia, Tracya, Urocystis). 
Key to Genera. 
I. Spores simple. 
A. Usually forming a dusty sorus at maturity (see also 
IB and IJJAza). 
1. Large, usually 16-35. 
a. With an elongated hyaline ees sauce 
Neovossia. 
b. Without a conspicuous appendage. Tilletia. 
2. Small to medium, usually 5-18. 
a. Sorus covered with a false membrane of 
definite fungous cells..... Sphacelotheca. 
b. Protecting membrane of plant tissue only 
(sometimes with gelatinized hyphe)...... 
Ustilago. 
B. More or less firmly agglutinated at maturity....... 
Cintractia. 
C. Permanently imbedded in leaves, praducing dis- 
COlMG. SNES aacsudbedueusesnaueeens Entyloma, 
II. Spores chiefly in pairs, forming an agglutinated sorus. 
Ss rhizomella, 
