iis 



in any one of the largest groups from those in all the others are 

 first given ; then under each of the largest groups follow the 

 essential characters distinguishing the next lower plant groups 

 from one another and so on, so that, if we compare the characters 

 of any given plant with those given in the Flora, we are led 

 quickly on from group to group until ultimately we arrive at the 

 smallest group and the correct name of our plant, without wast- 

 ing time or getting confused in reading and comparing long 

 descriptions of unimportant characters. 



Natural 106. It has been recognised from 



a very earl yP eriod tnat " h^e begets like," that, with plants 

 as w ith animals, the offspring resemble their parents, and hence, 



tion. also, it has been accepted as a fact from early times that all 



organisms which closely resemble each other must be nearly 

 related. 



When botanical classification was commenced, it became 

 necessary, first, to analyse and clearly define the essential points 

 of difference between individual plants, i.e. their characters, 

 and, secondly, to group together those plants with similar 

 characters. It was then found that, if only one character was 

 relied on, plants were often placed in entirely different groups, 

 although, as regards all their other characters, they were very 

 much alike and were in consequence held to be very closely 

 related. A system of classification, therefore, which only relied 

 on single characters, regardless as to whether, or not, the plants 

 which were most nearly related were thus kept together, was 

 known as an Artificial System, whereas a system, according to 

 which all characters were taken into account and which resulted 

 in placing the most closely allied plants in the same group, 

 was known as the Natural System. 



The best known example of an artificial system is the 

 so-called "sexual system" of Linnaeus. Under this system 

 only the characters of the stamens and the distribution of the 

 sexual organs in different flowers were taken into consideration, 

 and all known plants were accordingly classified under 24 groups. 

 As an instance of the artificial nature of this scheme of classifica- 

 tion it may be noted that Class XXI Moncecia includes two such 

 distantly related plants as the Maize (Zea Mays), a Monocoty- 

 ledon, and the Oak (Quercus), a Dicotyledon. 



A good artificial system which does not concern itself with 

 the fact as to whether nearly related plants are, or are not, kept 

 together in the groups which it defines, but which merely refers 

 to isolated and easily recognised characters, often enatyes us to 



