the plants to many eminent physicians at my room at the Fifth Avenue
Hotel; also before a medical society where more than one hundred persons
were present. I did all that I could, but such was the preoccupation of
the medical gentlemen that a respectful hearing was all I got. This is
not to be wondered at, as it was a subject, now, after the lapse of
nearly a decade and a half, quite unstudied and unknown. After this I
studied the plants as I had opportunity, and in 1877 made a special
journey to Long Island, N.Y., for the purpose of studying the plants in
their natural habitat, when they were in a state of maturity. I have
also examined moist soils in localities where ague is occasionally
known, with other localities where it prevails during the warm months.

Below I give the results, which from convenience I divide into two
parts: 1st. Studies of the ague plants in their natural habitat. 2d.
Studies of the ague plants in their unnatural habitat (parasitic). I
think one should know the first before attempting the second.

_First_--Studies to find in their natural habitat the palmellae described
as the Gemiasma rubra, Gemiasma verdans, Gemiasma plumba, Gemiasma alba,
Protuberans lamella.

_Second_--_Outfit_.--Glass slides, covers, needles, toothpicks, bottle
of water, white paper and handkerchief, portable microscope with a good
Tolles one inch eyepiece, and one-quarter inch objective.

Wherever there was found on low, marshy soil a white incrustation like
dried salt, a very minute portion was removed by needle or toothpick,
deposited on a slide, moistened with a drop of water, rubbed up with a
needle or toothpick into a uniformly diffused cloud in and through the
water. The cover was put on, and the excess of water removed by touching