AN INTRODUCTION TO ZOOLOGY. 



edges, which perform the same function, although in a 

 less perfect manner : the existence of rennet in the 

 plant is a curious fact in connection 

 ■with this habitj its natural use being 

 perhaps to digest the flies that are 

 caught. Probably numbers of 

 sticky glandular plants, such as the 

 " Catchfly," which owes its name 

 to this circumstance, are not above 

 o/MovtafslTef ^ol eking out their proper means of 

 .flXt aT^o'ihTfoeU subsistence by absorbing the juices 

 fnthSoZii ''(.m of such casual visitors as they hap- 

 '•'TeTSyofTtaS^^-; pen to despatch by means of their 

 stickiness. Besides these, again, 

 there are plants parasitic on other plants, such as 

 Mistletoe; or partly parasitic, such as the Dodder, 

 the Eyebright, the Yellow -rattle, and the Cow-wheat, 

 that twine their roots round those of another plant. 



The list of exceptions on the side of the animal 

 kingdom is not so formidable ; there are a few, which 

 will be mentioned presently. Meanwhile it may be 

 stated, that, in consequence of the resemblances exist- 

 ing between some forms, it has been proposed "^ to 

 class the lowest forms of animal and vegetable life 

 together as Protista; but this plan has not met with 

 general favour. It is, indeed, more remarkable that 

 such minute organisms can present so decisively and 

 definitely, as many of them do, those differences 



' By Prof. E. Haeckel. 



