260 Mr. W. S. MacLeay on certain general Laus regulating 



Animalia. Vegetabilia. 



Acrita .... Protophyta 



Radiata . . . Hysterophyta 



Annulosa . . . iNIonocotyledonea 



Vertebrata . . Dicotyledonea 



INIollusca. . . . P.seiuio-cotyledonea ? Agardh*. 

 Consequently some general idea of the primary distribution 

 of all organized beings may be obtained from the following 

 fiffure. 



To conclude : If an arrangement be natural, it will stand 

 any test; and to support the truth of this proposition, I shall 



now 



* This last department of the vccetable kingdom, Pseudo-colt/lcdoneat 

 has been defined by M. Agardh in the sixth part of his Aphorismi Botaiiici, 

 which is dated December 1821. According to him it embraces the jlTusci, 

 HepatlceE and Filiccs of Linnaeus ; and in page 76 of the same work we 

 find a comparison made between these plants and Amphibia, which is never- 

 theless much stronger when applied to them and the MoUusca. " Pseudo- 

 cotj'ledoneae Amphibiis non dissimiles, humum perreptant vel rimas quae- 

 runt, humiditateque gaudent ut ilia, organis jam in superiore sectione 

 deperditis iteriim instructae." In these last words he alludes to his own 

 opinion, that Mosses display organs nearly related to the cotyledons of 

 dicotyledonous plants, while the jnonocotyledonous plants conceal their 

 cotyledon; and if botanists should adopt this opinion, we might assimilate 

 it to the curious fact, that in the animal kingdom the imperfectly organized 

 MoUusca display a heart, which is more analogous to that of the Vertebrata 

 than the dorsal vessel of insects. With respect, indeed, to the analogies 

 existing between the animal and vegetable kingdoms, they are too striking 

 to have altogether escaped the notice of such an observer as Agardh, who 

 truly observes, "Memorabilis est analogia evolutionis seriei vegetabilis cum 

 animali." When we find him, however, comparing the least perfect vege- 

 tables to some of the most perfect animals, the Alga to Fishes, and the 

 Lichenes to Insects, %.e must suspect that he is not sufficiently acquainted 

 with the evolution of the aninial series, and conclude that he has at least 

 not Bufficiently attended to the parallelism of analogy. Nevertheless, his 

 comparison of Monocotyledonous, or, as he terms them, of Cryptocotyle- 

 donous Plant! to Birds, appeal* to be a true relation .of analogy, although 



an 



