SATYK. 



by Mr. Pritchard in the Microscopic Cabinet. The real length of 

 the creature, measured from the extremity of the antennae to 

 that of the tail, was eight-tenths of an inch. It is repre- 

 sented in the figure, as seen in profile, the breadth of the head 

 and other parts being necessarily foreshortened. 



A system of trachea?, with numerous ramifications, passes along 

 each side of the body from the head to the tail, one of which is 

 seen in the figure. These respiratory apparatus ramify in a 

 beautiful manner in the triple branches of the tail, each of which 

 receives a branch from each trachea. 



During its growth the larva casts its skin several times, and 

 the skin which it thus throws oft', being translucent, is an inter- 

 esting and beautiful microscopic object. 



The eyes as well in the larva as in the perfect insect are very 

 salient, and from their magnitude and structure form interesting- 

 microscopic objects. Like those of some other insects described 

 in a former Tract,* they consist of a multitude of distinct organs 

 of vision, each of which is an hexagonal lens. It was observed 

 by Latreille, that their number increased in proportion to the 

 voracity of the insect. Leuwenhoeck counted 12000 in a single 

 insect. Each hexagon is a convergent lens, which may be 

 converted into a microscope. Each of these lenses is found 

 to produce an inverted image of an object to which it is 

 presented. 



3. The object shown in fig. 3, engraved from a drawing by Dr. 

 Goring, and described in the Fig> 3 . 



Microscopic Cabinet by Mr. 

 Pritchard, belongs to the class 

 of animalcules denominated 

 by Miiller monoculi, from the 

 circumstance of their having 

 a single organ of vision, , 

 placed in the centre of the 

 front of the head. This 

 specimen is called the satyr, 

 and is the amymone satyr of 

 Miiller. The figure represents 

 a magnified view of the full- 

 grown insect, seen at the in- 

 ferior surface of its body as 

 it presents itself to the observer, attached to the inner surface of a 

 vase of water in which it moves. The real length of the animalcule 

 here represented was the 120th of an inch. When they are 



* "Microscopic Drawing and Engraving," p. 50. 



91 



