228 The Microscope. 



living creatures seem to subsist upon water alone; but when it is 

 stored with their proper food, myriads may be found in every 

 drop, of the greatest variety in their forms; some are round, some 

 oblong, and others spherical, and the greatest part of them trans- 

 parent: motion seems to be their greatest delight; they pervade 

 with ease and the greatest rapidity the whole dimensions of the 

 drop of water, in which they find ample space; sometimes they 

 dart forwards, and at others move obliquely, then again in a circle, 

 and though hundreds may be seen in a single drop, yet they never 

 strike against one another: they differ in their size; some are 

 barely visible to the eye; some so minute as to resist the action 

 of the microscope, and appear only as moving points; of this de- 

 scription is the monus; it is so extremely delicate and transparent 

 as sometimes to elude the highest magnifying power: some are no 

 doubt inhabitants of the water, and others turn into small flies, and 

 deposit their eggs in any kind of fluid producing proper nourish- 

 ment for their young; the eggs being hatched, they live a certain 

 time in this element, then take wing after a complete change in 

 their forms; this may often be observed, for when they grow to a 

 certain size, of a sudden you will find them gone, and a small race 

 supply their place. 



As these infusions to produce them, are all prepared in a sim- 

 ilar manner, and as the two following substances maybe procured 

 without much trouble, and generate the most remarkable subjects, 

 we shall describe the necessary preparations. 



Hay. The infusion of hay produces the greatest variety of ani- 

 malcules, and by far the most curious; all those described in the 

 plate may at different times be found in this infusion. Twist up 

 a little hay, and press it down into a teacup or any other vessel; 

 cover it with water to the top, and if it absorbs the water, put 

 fresh in; in a few days, in summer, a scum will appear on the top; 

 take from the surface, with the spoon at the end of the forceps, a 

 single drop, and place it between the glasses; it will be found to 

 contain extremely minute animalcules: in a few days they increase 

 in size, and in about ten days they obtain their full growth. It is 

 impossible to enumerate the variety that may be discovered at 

 different times in this infusion; the most numerous are in the shape 

 of an egg, fig. 1. PI. 8. and with a high power a gr6at number of 

 small feet may be discovered, and at the head a number of fabrilla, 

 which are continually in motion, creating a vortex in the water 

 which brings their prey towards them, which may be discerned 

 many hundred times less than themselves; they use their legs in 

 running as well as swimming, for by placing a hiunan hair across 

 t>'' water, as fig. 2, a number of them will be seen running along 



