58 



As to gome of the animalcules observed by Lewew- 

 hoeck, he computed, that three- or four hundred of 

 them placed close together iu a line, would only equal 

 the diameter of a grain of sand. Twenty-seven mil- 

 Jions then of these animals equal in bulk a grain of 

 sand. 



But Hartsoeker carries the matter still farther. Jf ? 

 says he, according to our present system of genera- 

 tion, all animals were formed from the beginning of 

 the world, and enclosed one within another, and all 

 of them in the first animal of each species : how mi. 

 nute must the animalcula produced now, have been at 

 the beginning ? 



0. Even the meanest and most contemptible of in. 

 sects, shews the wisdom of its Creator. Fleas, for 

 instance, deposit their eggs only on such aiiimals, as 

 afford them a proper food* These hatch into worms 

 of a shining pearl-colour, which feed on the scurif of 

 the cuticle. In a fortnight they are very active, and 

 if disturbed, suddenly roll themselves into a ball. Soon 

 after they begin to creep with a very swift motion. 

 When arrived at their full size, they spin a thread 

 out of their mouth, wherewith they form themselves a 

 case. After a fortnight's rest here, each of them 

 bursts a perfect flea, leaving its exuviae behind. It is 

 milk white till the second day before its eruption : 

 then it changes colour and gets strength, so that 

 upon its first delivery, it springs nimbly away. . 



Minute animals are found proportionably much 

 stronger and more active than large ones. The spring 

 of a flee iu it's leap vastly exceeds any thing greater 

 animals are capable of. Mr. De Lisle has computed 

 the velocity of a little creature, which ran three 

 inches in half a second. Now supposing its feet to 

 be the fifteenth part of a line, it must then, iu order, 

 to travel over such a space iu such a time, make five 

 hundred steps 114 the space of three inches: that is,, 

 it must shift its feet five hundred times in a second, or 

 in th-e ordinary pulsation of an artery. What is the 



