296 THE INDUCTIONS OF BIOLOGY. 



attributes are possessed. In 1703, some thirty years before 

 the time of Linnoeus, our countryman Ray had sketched the 

 outlines of a more advanced system. He said that — 



Plants are either 



Flowerless, or 



Flowering ; and these are 

 Dicotyledones, or 

 Monocotyledones. 

 Among the minor groups which he placed under these 

 general heads, " were Fungi, Mosses, Ferns, Composites, 

 Cichoraceae Umbellifers, Papilionaceous plants, Conifers, La- 

 biates, &c, under other names, but with limits not very dif- 

 ferent from those now assigned to them." Being much in 

 advance of his age, Ray's ideas remained dormant until the 

 time of Jussieu ; by whom they were developed into what 

 has become known as the Natural System. Passing through 

 various modifications in the hands of successive botanists, 

 the Natural System has now taken the following form ; which 

 I copy (adding the alliances to the classes) from Prof. 

 Lindley 's Vegetable Kingdom* 



* From this table I have omitted the class Rhizogens, which other botanists 

 do not agree with Lindley in regarding as a separate class. The plants respect- 

 ing which there has arisen this difference of opinion, are certain flowering 

 plants, which grow parasitically on the roots of trees. The reasons assigned by 

 Endlicher and Lindley, for erecting them into a separate group of Phaenogams, 

 are, that in place of true leaves they have only cellular scales ; that the stem is 

 an amorphous fungous mass, imperfectly supplied with spiral vessels ; ana that 

 they are without chlorophyll. Mr Griffith and Dr Hooker, however, have given 

 preponderating reasons why they should be restored to the class Exogens. It 

 seems here worth remarking, that certain zoological facts suggest an explanation 

 of these anomalous botanical facts ; and confirm the conclusion reached by Dr 

 Hooker and Mr Griffith. It very commonly happens that animal-parasites are 

 aberrant forms of the types to which they belong ; and, by analogy, we may not 

 unreasonably expect to find among parasitic plants, the most aberrant forms of 

 vegetal types. More than this is true. The kind of aberration which we see in the 

 one case, Ave see in the other ; and in both cases, the meaning of the aberration is 

 manifest. In such Epizoa as the Zernece, the Crustacean type is disguised by the 

 almost entire loss of the limbs and organs of sense, by the simplification of the 

 digestive apparatus, and by the great development of the reproductive system: 



