THE SYNCHAETA BALTICA. 269 
their ordinary position when keeping their wheels in action for 
a supply of food or of water; but they have no difficulty in 
letting go their hold, and either creeping along by alternate 
contractions and extensions or swimming away in search of a 
new attachment. From the neck projects a telescopic spur, 
supposed to be an organ of respira- 
tion, and just below this are seen two 
minute red specks, supposed to be 
eyes. The first rotifer was discovered 
by Leeuwenhoek, in 1702; now more 
than 180 species are known, and new 
discoveries are constantly adding to 
their numbers. They are chiefly found 
in sweet water, but some are inhabitants 
of the sea, as, for instance, the Syn- 
cheta baltica, remarkable for its lu- 
minous powers. It measures about 5415 
of an inch in length, and but 53, in 
width, so that it is invisible to the 
sharpest unassisted sight: but when 
viewed through a microscope, it appears 
as a beautiful and richly organised 
creature, clear as glass and perfectly 
colourless, except that its stomach is 
usually distended with yellow food, 
and that it carries a large red eye, which 
glitters like a ruby. 
“Its motions too,” says Mr. Gosse, 
“are all vivacious and elegant. It 
shoots rapidly along or circles about 
in giddy dauce, in company with its 
fellows, sometimes near the surface, at — pnilodina roseola—(Fighly 
: x ed. 
others just over the bottom of the vase See 
é jf ee ; a. Respiratory tube. 
in which it is kept. Occasionally the  % Alimentary canal. 
ior: with the iny- tocspis drawn. up: ©: Letina intestinal poueb- 
into the body and then suddenly thrown 
down, and bent up from side to side as a dog wags his tail. 
Sometimes the rotatory organs are brought forward and then 
spasmodically spring back to their ordinary position, when the 
little creature shoots forward with redoubled energy. In all its 
actions it displays vigour and precision, intelligence and will.” 
