197 



the ostrich, or from the sea nettle to the ouran-outang. 

 Plants, being essentially more simple than amuml % have 

 not given birth to so many combinations. 



The forms of animals afford us a* singularity winch is 

 extremely remarkable, and sufficient to distinguish 

 them from vegetables ; I mean, those admirable meta- 

 morphoses which tho same insects exhibit to us, which 

 are sometimes so opposite, that it does not appear to be 

 the same animal. 



But may we not compare the bud in which a plant or 

 flower is infolded, to the covering of a chrysalis which 

 conceals the butterfly from our si^ht ? And as the plant 

 cannot produce seeds till th? t1>wer has issued from the 

 bud, so neither can the butterfly propagate till it has cast 

 off the sheath of \\\& chrysalis. 



18. It is not so easy to ecrnpr,^ pianfs and animal's 

 in their interior forms or structure, as it is in their ex- 

 terior. We may judge of the one by a single glance of 

 the eye : we must bestow a particular attention, to judge 

 of the other. We penetrate with greater difficulty, into 

 the inside of a plant, than into that of an animal. The 

 microscope, scalpel, and injections, which are so ser- 

 viceable to us in the anatomy of animals, assist us very 

 imperfectly in that of plants. It is likewise true, that 

 this part of organical economy has been less studied. 



But how imperfect soever the anatomy of plants may 

 1>e, we are able to discover some of their principal vessels. 

 These may be ranged under two general classes ; the 

 longitudinal that extend the whole length of the plant, 

 and the transverse vessels, or such as are placed across 

 it. The sappy vessels and tr achaean belong to the first 

 class ; the utriculi, or insertions, to the" second. The 

 vessels containing the sap seem designed to convey the 

 juice. The utriculi, or little bags, appear intended for 

 digesting it. 



Some plants seem to be entirely composed of utri~ 

 K 2 



