OF VEGETABLE SYMMETRY. 303 



forms so rare, that it seemed almost impossible to dis- 

 cover any general law ; by degrees it was perceived that 

 almost all, and probably all amorphous bodies might be 

 reduced to the form of crystals, and, consequently, that 

 regularity existed in their nature. Among crystals 

 themselves, it was perceived that a number of very 

 different forms were simple modifications of a few primi- 

 tive ones ; these primitive forms have not only been 

 reduced to a very small number, but the principal cir- 

 cumstances which determine the secondary forms have 

 been arranged ; and here, as in a great number of dy- 

 namic phenomena, it has been seen that the irregularities 

 result from the simultaneous action of several regular 

 causes which are increased and complicated in the 

 results. 



If we examine more closely the progress of Crystal- 

 lography, we shall see that Rome-de-lTsle, considering 

 crystals as single bodies, explained their anomalies by 

 truncations, whilst Haiiy, going back in theory to the 

 primitive molecules, although they do not come under 

 our observation, was enabled to explain, in the most 

 happy manner, the most complicated forms, by referring 

 them to the different modes in which the molecules are 

 united together. The first reasoned as those botanists 

 do, who consider a leaf or corolla as a single whole, 

 notched upon its margins from some unknown cause ; 

 the second has served me as a guide, when I attempted 

 to show that the different indentations, or divisions of the 

 organs of plants, were essentially connected with the 

 various modes and different degrees of their aggregation. 



There has been, then, a similarity in the progress of 

 these two sciences ; let us now see if there be any in 

 their nature. 



Does this regularity exist in organized bodies, and 

 can the anomalies, so frequent in thenij be owing, as in 



