96 NATURAL HISTORY 



GENUS IX. 

 GONIUM. 



The animalcules of this genus are in clusters ; they are 

 propagated by several incisions across the body of the 

 parent, dividing it into a number of symmetrical forms. 

 When observed singly, most of the species resemble the 

 genus Volvox. The structure of their digestive organs is 

 unknown : as microscopic objects, they are very pleasing 

 and entertaining, and only require a moderate power 

 for their examination. In the Achromatic and Jewel 

 Microscopes their bright and transparent colours are 

 beautifully exhibited, and by the employment of intense 

 illumination, moderated in quantity by diaphragms, as 

 described in the " Microscopic Cabinet/' their forms, 

 change, colour, and motions, may be observed with ease. 

 Muller defined this genus as composed of " invisible, 

 simple, smooth, angular animalcules." 



165. GoNiUM pectorale. The breast-plate Gonium. — 

 The form of this animalcule, or, more correctly, cluster 

 of animalcules, is shewn at figure 93. It consists of 

 sixteen spherical bodies, disposed regularly in a quadran- 

 gular form, like the jewels in the breast-plate of the 

 Jewish High Priest. They are all arranged in the same 



