SECT. III. GEMS. 413 



3. Because in the Confervtf two or more of 

 them often coalesce, and yet form but one indi- 

 vidual. 



In reply to the first argument, Mr. Correa main- 

 tains that the grains of the Ceramiums and Ulvce 

 are precisely similar to those of the true Fuci 9 en- 

 closed in a uterus enveloped with a soft and juicy 

 substance, affixed no doubt by some placentation, 

 furnished with a proper skin, and disengaging them- 

 selves from the parent plant at the period of their 

 maturity, though Gaertner says only by the plant's 

 decay. 



In reply to the second argument Mr. Correa does 

 not pretend directly to controvert the fact which he 

 seems to think no observation can accurately ascer- 

 tain, but merely the principle by which it has been 

 supposed that no substance can possibly be a seed 

 unless it has a coat to leave behind it in germinating, 

 and that no substance can be a gem if it has one; 

 a principle arising, as he thinks, out of the supposed 

 analogy between the seed of vegetables and eggs of 

 animals, or between the gem and the living foetus : 

 but gems, as he asserts, do sometimes leave a coat 

 behind them, as in the scales of the bud ; and eggs 

 have sometimes no coat to leave, as in the spawn of 

 Frogs. 



In reply to the third argument he contends that 

 its scope is precisely the reverse of that alleged by 

 Gaertner, because it is known that in the case of the 

 coherence of other acknowledged gems, the one 



