472 NINETEENTH CENTURY. FT. in. 



it came to be what it is and where it is, did not arise. 

 Rut now, taking a plant, for example, we have to learn in 

 what it differs from the simplest plants known, and for 

 what reasons it has gradually acquired the various parts by 

 which it performs its functions. From this point of view, 

 its roots and the way they grow, its leaves, the hairs that 

 cover them, the chlorophyll which they use to assimilate 

 their food, even their movements by night or by day, have 

 all a real significance, as Dr. Julius Sachs has so graphic- 

 ally described in his works. Again, the study of the 

 curious structure of flowers, their manner of forming, their 

 seeds, and the numerous contrivances for attracting or 

 repelling insects, has become a science in itself, enriched by 

 the countless observations of Darwin, Hermann Miiller, 

 Kerner, Sir John Lubbock, and others. Yet still so much 

 remains to be done that any one who will work in the 

 field or garden, with the theory of evolution as his guide, 

 may add to the links in Nature's chain, by following which 

 we are gradually tracing out the past history of plant life. 



In the same way the food of plants, and the manner in 

 which many have been driven to procure it, so to speak, 

 illegitimately, now offers a new line of research. Parasites, 

 epiphytes, saprophytes, all help us to trace out ' adaptations 

 to changed conditions of life,' and to learn how a plant 

 loses organs, or gains new ones, as it leaves the ordinary 

 road of plant life. 



Take, for example, the carnivorous plants, such as the 

 Dionaea, the Drosera or sun-dew, and the Pinguicula, which 

 actually feed upon the juices of insects and other small 

 animals which they enclose in their leaves. As long ago 

 as 1768 an English botanist named Ellis pointed out that 

 the leaves of the Dionsea close over any unfortunate 

 insect which alights upon them, and cover it with a sticky 



