
Plate XVIII. 1, Uroglena-x300; 2, Spirogyra-x500; 3, Resting spores of Spirogyra-x500; 4, Chlamydomonas showing resting condition of reproductive bodies-x1000
Illustrated by D.G. Passmore
Printed by Gray Lith. Co. N.Y.
The Yearbook of the United States Department of Agriculture-1902
Washington: Government Printing Office, 1903
Gould Library Government Documents
The physiologist George T. Moore explains the importance of clean water and the threat posed by algae. The Spirogyra in this image is described as one of the most troubling forms of algae:
In at least one instance this algae has been the cause of the loss of thousands of dollars by the damage it produced in smothering out the young water-cress plants in the artificial beds constructed for the winter propagation of this vegetable…
George T. Moore

Plate XIX. 1, Clathrocystis-x500; 2, Anabaena-x500; 3, Oscillatoria-x500; 4, Asterionella-x500; Navicula showing structure of diatom-x500
Illustrated by D.G. Passmore
Printed by Gray Lith. Co. N.Y.
The Yearbook of the United States Department of Agriculture-1902
Washington: Government Printing Office, 1903
Gould Library Government Documents
The physiologist George T. Moore explains the importance of clean water and the threat posed by algae. The blue-green in this image are associated with causing bad odor and taste.
In addition to what may be regarded as decomposition effects, some of the blue-greens possess a natural odor and taste, due to the presence of an oil, which upon being liberated produces a most disagreeable result. When very strong, the odor has been likened to raw green corn or to nasturtiums, but usually it can not be likened to anything so pleasant…
George T. Moore