350 THE MICROSCOPE. 
being and even a susceptible one.—Report of the Maine State Board 
of Health, 1888. 
Prof. Cohn, of Breslau, one of the best authorities on bacteria, 
has recently called attention to the remarkable work of Leeu- 
wenhoek done in this same department of research more than 
two centuries ago, before the compound microscope came into 
use. This pioneer microscopist observed in the cleanings of his 
teeth several kinds of organisms which are now known to belong 
to the Schizophytes, and described them so accurately that they 
are easily recognized. One he said “resembled a rod” (Bacillus); 
others had the habit of “bending in curves” (bacteria); others 
of “creeping in a snake-like fashion ;” and another kind, “ ex- 
tremely minute, resembled a swarm of flies rolled up in a ball” 
(Micrococcus). When it isremembered that this group of plants 
includes the most minute of all organisms, it is a matter of 
astonishment that this old naturalist should have been able to see 
so much with such imperfect instruments as were at his command. 
His microscopes were beads of glass of various sizes which he 
made himself. It affords another illustration of the fact that 
genius consists in the power of doing much with little. 
It is well known, as stated by Darwin, that fresh-water mussels 
and other animals may by adhering to the feet of aquatic birds, 
such as ducks and wading birds, be transferred from one stream 
or pond to others. Thus may be partly, at least, explained the 
similarity of the fauna in widely separated inland basins. But 
except the isolated observations of Darwin and a few others, little 
has been done to find out definitely what animals might be thus 
distributed. M. Jules de Guerne has lately made a careful exam- 
ination of the organisms found in the particles of slime adher- 
ing to the feathers, bills and feet of wild ducks (Anas boschas) 
The webbed feet were washed with especial care, and a micro- 
scopic examination of the water revealed the presence of little - 
nematode worms, Rotifers (Philodinide), Rhizopods (Trinema 
enchelys), Diatoms, Desmids, numerous, encysted organisms, isol- — 
ated eggs of cladocerous crustacea, pieces of polyzoon statoblasts 
(Plumatella), and the shell of an astracod (Cytheridea torosa). 
Spores and cysts were also found in slime particles taken from 
the feathers. 
DIssEMINATION OF BacrILLus By FLIEsS—MM. Spillmann and 
