222 TRANSLATIONS AND SELECTED ARTICLES. 



has occurred whicli tends to prove that the structure of vegetahles 

 has not a general correspondence with their natural affinities. Of this 

 kind we find clear characters for the three great sub-kingdoms. In 

 each of them the plants have an internal structure very different from 

 that which belongs to the adjoining sub-kingdom, and are sufficiently- 

 distinguishable by their anatomical construction. 



One of these sub-kingdoms, that which occupies the lowest place, 

 has been examined with great care in reference to this matter. All 

 inquiries have confirmed the principle of the importance of anatomy. 

 It is by a character exclusively anatomical that the great group of the 

 Acotyledqnes [flowerless plants, or Cryptogamia] has been divided into 

 two secondary groups — Vascular and cellular plants.* 



The importance of anatomy by no means appears less, if in each 

 of these sub-divisions we examine the mutual relations of classes and 

 families. The structure of the Horse-tails, Ferns, Lycopodiacese, 

 and Marsiliaceae, does not less certainly than characters drawn from 

 their vegetation and reproduction distinguish these orders one from 

 another. 



The same may be said still more decisively of the entirely cellular 

 plants whose extreme simplicity causes the essential characters upon 

 which their most important groups are founded, to be often no more 

 than anotomical characters, implying important modifications of" or- 

 ganic functions. 



In the sub-kingdom Monocotyledonese, it is a very long time since 

 Daubenton and Desfontaines {Memoires de VIst. an vii.), as the 

 result of numerous examinations of different palms, pointed out as 

 common to the whole sub-kingdom, an anatomical disposition of parts 

 alogether peculiar, and contrary to the internal structure of Dicotyle- 

 doneee. According to these writers the stem of a woody Monocoty- 

 ledonous plant is of less close texture towards its centre, because at 



* Many of our readers are probably more accustomed to see the cryptogamic sub-kingdom 

 of plants divided at once, as we ourselves recommend, into three classes, which may be 

 named Acrogens, Anogens, and Thallogens, In the first there is always more or less ap- 

 proach to a vascular system, thoush never either all the kinds of vessels, or any simUar 

 arrangement of them, which are found in higher plants, and the true reproductive organs 

 are found in a prothallus. In the second, with a structure entirely cellular, there is always 

 more or less distinction of stem and foliage, the green colour of vegetation is retained, and 

 the archegonia are produced ou some point of the plant itself— not on a prothallus. In the 

 third the stem and leaves are more or less completely confounded together, other colours 

 are substituted for the usual vegetable green, and lower reproductive types prevail. It is 

 obvious that this difference of method does not affect the author's argument. 



