54 NOTES ON 
produced, are drawn within the parts above, and 
slide out like the tubes of a telescope, when the 
joint disappears. It is this power that enables 
it to assume the form of a sphere, the head and 
tail bemg drawn within the body. This is 
shewn as nearly accomplished in figure 6, the 
toes (g), however, being still attached to a stem. 
In jfiyure 7 it is entirely withdrawn, and forms 
a ball, in which state it moves about spontane- 
ously, and exhibits only the vortex (a), which is 
also seen in figure 6. 
The folds and external markings which pre- 
sent themselves in’ these forms exhibit the man- 
ner in which the body has contracted, and re- 
quire attention to develope them. It is while 
in the form of figure 7 that they remain torpid. 
So great is their tenacity for life, that Leeuwen- 
hoek states, and it is confirmed by Baker, that, 
having kept some of the sediment containing 
them, found in leaden gutters “as dry as clay,” 
for twenty-one months, when infused in water, 
multitudes soon appeared, unfolding themselves, 
and putting out their wheel-like organs in 
search of food. These creatures feed on small 
animalcules and vegetable matter, some of which 
is seen approaching it in the direction of the 
arrows, figure 1. In preserving them, care 
