10 



HUTCHINSON'S POPULAR BOTANY 



longer one quiescent body, but four: so that when the outer investing 

 sack in which they are all contained gives way, they emerge as perfect 

 individuals. Each will have its own independent history ere long per- 

 chance a very different history from that of the parent body : for from 

 each may issue, not fully clothed individuals like themselves, but naked, 

 motile bodies, like those from which the parent was evolved, with pear- 

 shaped forms, and scarlet eye-spots, and delicate filaments that possess 

 the power of contraction. Thus the round of life goes on. 



But let us pause and ask, What are these changeful little bodies 



these minute organisms, so simple 

 and yet so wonderful ? To which 

 of the two great realms of living 

 Nature do they belong ? Are 

 they animalculse. or plants '? 

 " Surely," it might be urged, 

 "they belong to the Animal 

 Kingdom the little motile 

 bodies tell us that." Yet the 

 fact is otherwise. Those tiny 

 organisms are plants, true plants, 

 and their names must not be 

 sought for in any zoological cata- 

 logue. Their habits are, indeed, 

 strikingly similar in some re- 

 spects to those of many minute 

 animals ( Vorticella microstoma, 

 for example) ; yet are they true 

 plants ; and the active little 

 bodies, with red eye-spots and 

 antennae-like prolongations, are 



neither more nor less than the 

 FIG. 23. BELL-ANIMALCULE (Vorticella). ,-, ni f 



motile cells or zoospores oi our 



A microscopic animal belonging to the Protozoa, but plant-like . , . , , , c ; /' 



in appearance. Much magnified. Slllgle-Ce lie d plant, bptHXreUa 



pluvialis. 



Yes, plants ; and each individual is a single cell, though it is only 

 after it acquires its coat of cellulose that it becomes a cell in the common 

 acceptation of the word. It is an unicellular plant, and so is distinguished 

 from the great mass of plants, which are multicellular, or made up of 

 many cells. And thus we are brought to a very interesting truth, and 

 one of vast importance to the student of Botany viz., that every plant 

 in the wide world, from the highest to the lowest, consists either of a cell 

 or cells. We shall see farther on that the living matter (or protoplasm, 

 as it is called) is the essential part of the cell ; indeed, there is evidence of 

 this in the active spores of Sphcerella, which, prior to the formation 



