220 NICOLAUS STENO 



and again seen the roots of small plants, without any 

 covering of earth at all, clinging to the surface of the 

 tuff. Thus the place where the orange grows, after 

 the blossom has fallen, is partly the peduncle continu- 

 ous with it, and partly the air contiguous to it. Thus 

 the place where the first growth occurs in animals, is 

 partly the amniotic fluid contiguous to it, and partly 

 the umbilical vessels scattered through the chorion, 

 continuous with it. 



Ill 



If a solid body has been produced according to the laws of 

 nature, it has been produced from a fluid. 



In the production of a solid body, both its first outlines and 

 its growth should be taken into account; but as I freely con- 

 fess that the outline of most of the bodies is not only doubtful 

 to me, but wholly unknown, so do I believe, without any hesi- 

 tation, that nearly all the following statements concerning their 

 growth are true. 



A body grows while new particles, secreted from an external 

 fluid, are being added to its particles. This addition, more- 

 over, takes place either immediately from an external fluid, or 

 through one or more mediating internal fluids. 



The additions which are made directly to a solid from an 

 P- 19- external fluid sometimes fall to the bottom from their own 

 weight, as sediments do ; sometimes the additions are made to 

 a solid on all sides from a fluid bearing matter toward the solid, 

 as in the case of incrustations ; or the additions are made only 

 to certain places of the solid surface, as in the case of those 

 bodies which present fibres, branches, and angular bodies.^ 

 Here it must be noted in passing that the processes mentioned 

 sometimes continue until an entire cavity is filled with such 

 additions, and hence replacements occur which are sometimes 

 simple, are sometimes formed from incrustations, sometimes 

 from sediments, sometimes from angular bodies, and some- 

 times from various bodies variously intermingled. 



The particles which are added to a solid by a mediating 



^ Angulata corpora is the phrase used by Steno to denote crystals in general ; crystallus is 

 confined to quartz. See p. 218, n. i. 



