118 LEEUWENHOEK AND HIS “‘ LITTLE ANIMALS” 
Water-flea, or Water-louse,’ which you can see alive and 
moving in water with the bare eye. 
Of the first sort that I discovered in the said water, I 
saw, after divers observations, that the bodies consisted 
of 5, 6, 7, or 8 very clear globules, but without being able 
to discern any membrane or skin that held these globules 
together, or in which they were inclosed. When these 
animalcules bestirred ’emselves, they sometimes stuck 
out two little horns,’ which were continually moved, after 
the fashion of a horse’s ears. The part between these 
little horns was flat, their body else being roundish, save 
only that it ran somewhat to a point at the hind end; at 
which pointed end it had a tail, near four times as long 
as the whole body, and looking as thick, when viewed 
through my microscope, as a spider’s web.* At the end 
of this tail there was a pellet, of the bigness of one of the 
globules of the body; and this tail I could not perceive 
to be used by them for their movements in very clear 
water. These little animals were the most wretched 
creatures that I have ever seen; for when, with the 
pellet, they did but hit on any particles or little filaments ° 
(of which there are many in water, especially if it hath 
* Swammerdam’s “ watervlooy’”’ was Daphnia—as all students of the 
Biblia Naturae are well aware (cf. B.N. Vol. I, p. 86, Pl. XX XI). But as this 
work was not published until 1737—long after his death—it is clear that 
L. here alludes to his earlier Dutch publication (Swammerdam, 1669), in 
which the water-flea is shown on Pl. I. Swammerdam himself called it 
“the branched water-flea”’, and attributed the name ‘‘ water-louse’’ to 
Goedaert. 
> Vorticella sp. The following admirable description makes the 
identification certain. 
* The optical section of the wreath of cilia round the peristome—so 
interpreted by most of the early observers. 
* i.e., as thick as a spider’s web looks to the naked eye. 
a9 
> maer quamen aen eenige deeltgens of veseltgens MS. ° if they chanced 
to light upon the least filament or string, or other such particle’? Phil. 
Trans. These words of Oldenburg are amusingly mistranslated by Nagler 
(1918, p. 7) ““ Wenn man diese kleinen Kreaturen Zufallig belichtete.” (He 
apparently supposes that “ to light upon’”’ means “‘ to illuminate ” ! ) 
