PARAMAECIUM AURELIA AND PARAMAECIUM 
CAUDATUM 
LORANDE LOSS WOODRUFF 
From the Sheffield Biological Laboratory, Yale University 
ONE FIGURE 
Leeuwenhoek in 1677 described! some ‘‘little animals longer 
than an oval’”’ which he had discovered two years previously, 
and there is some reason to believe that this is the first published 
record of an organism belonging to the genus Paramaecium. 
The name Paramaecium, however, was first employed by Hill? 
to designate certain small organisms which were more or less 
oblong, -in contrast to others which were round or decidedly 
vermiform, and either the present species aurelia or caudatum 
is probably the animal which he designated as ‘Paramaecium 
species 3.’ 
Although Hill was the first to attempt to apply scientific names 
to microscopic animals, it remained for O. F. Miiller to give 
a general classification of these forms, and to apply the Linnean 
nomenclature. He began this work on the infusoria as a sec- 
tion of a treatise entitled, Vermium terrestrium et fluviatilium His- 
torta, which appeared in two volumes in 1773. Unfortunately 
he did not live to see the publication of his special work, Animal- 
cula Infusoria fluviatilia et marina, 1786, which was edited by his 
friend, O. Fabricius. Miller described a Paramaecium and ap- 
plied the specific name aurelia in the former of these works. In 
the latter work he described and figured? Paramaecium aurelia 
’ 
1Philosophical transactions, London, 11, 133. 1677. 
*History of animals, 3, 1751. 
3Plate 12, figs. 1-14. 
JOURNAL OF MORPHOLOGY, VOL. 22, No. 2 
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