CHAP, ii.] CHEMISTRY, ETC., OF PLANT LIFE. 81 



certain portion by a means which, if secured at a less 

 cost in the first instance, leads eventually to a compara- 

 tive loss of freedom and individuality. All the species 

 enumerated only grow and flourish when in close contact 

 with other plants. In every instance the seeds on ger- 

 mination give origin to a root that in the first instance 

 derives food by absorbing water from the soil, but this 

 first-formed root soon perishes, and the later-formed or 

 secondary roots become attached to the roots of other 

 plants, from which they draw the liquid portion of their 

 food. If seeds of either of the above plants are inten- 

 tionally sown apart from other plants, it will be found 

 that after a very brief existence they die, having become 

 so far differentiated on the road towards parasitism, that 

 their roots cannot take in food direct from the soil, yet 

 in every example the leaves are still green and capable of 

 assimilation. It is interesting to note that in the earliest 

 condition, that is, immediately after the germination of 

 the seed, the young plants obtain all their food by the 

 typical method. In the tooth wort (Lathrcea squamaria) , 

 and the species of broomrape (Orobanche), the change 

 in the direction of parasitism has been carried much 

 further ; not only has the chlorophyll been completely 

 suppressed, but even the leaves themselves have become 

 reduced to mere scale-like structures of no functional 

 value, and the plant depends entirely on its host for its 

 supply of already assimilated food, the only trace of 

 individuality retained by such pronounced parasites 

 being the power of rearranging the food thus obtained 

 and building up the reproductive portion of their dege- 

 nerated structure. In extreme cases of parasitism, as 

 illustrated by the species of Rafflesia, natives of the 



a 



