isms to search for differences, does not seem a promising line of research 
because negative evidence would be valueless, while positive evidence 
would be obtained only most rarely, even though saltation is very com- 
mon. Since, even in my most rapidly saltating strains, changes occur in 
only 1 out of 5,000,000 cells, and re-isolations from soils would give col- 
onies from single conidia only, that is, from a small group of cells, the 
evidence of saltation by this method of investigation could reasonably be 
expected only once in several thousand platings. 
NOTES CONCERNING SELECTED INDIVIDUAL SALTANTS 
Unless otherwise noted the permanence of the saltant characters 
were tested by repeated transfers. Colony-characters were determined 
on corn-meal agar; measurements of conidia and other conidial characters, 
under standard conditions. 
M1. Origin slightly zonated (Pl. XXIII, 1), few conidia. M1-1 grew 
faster than its origin; ratio, 6.5:8; characters maintained through several 
transfers. 
Mo-1. Much like M1, but with decided difference in conidial breadth 
(Graph 70, Fig. Q). 
M8. Growth slow; conidia few, pale, and thick (Fig. Q); septa 
few. The squarish cells very striking; differences apparent also on green- 
wheat agar. 
M12-3. Quite distinct in septation and breadth. As toconidial length, 
see Graph 121, Fig. Y, and data. 
M17-3. A distinct variant in thickness, septation, and shape. As to 
conidial length, see Graph 138, Fig. Y, and data. 
M26. (See page 143, and Pl. XXX and XXXI1.) 
M35. Characterized by its very short conidia (see page 141 and 
Fl. X XVI, c). 
M36. Derived from a single-conidium culture; conidia thick. 
M38. The colony had much aerial mycelium and was quite white, 
though a shade of black from the surface-agar showed through (Pl. XXVII). 
It continued through many transfers as a pale form with scant conidia. 
M533. (Pl. XXX). Very different from its origin, being covered with 
much loose, white, aerial mycelium, rendering the whole colony white and 
fluffy in appearance, while the original colony was neither white nor fluffy. 
M54 and M55. These also were two white, woolly colonies. 
M56 (origin, Pl. XXX) and M60. These were from a dark fast- 
growing sector of M26 and maintained character. 
