26 



HUTCHINSON'S POPULAR BOTANY 



plant, but of the Common Bean 

 (Vida faba), are fairly uniform. 

 The solitary stellate cell in the 

 next figure (fig. 45) is not so regu- 

 lar. It is a Desmid one of a 

 remarkably beautiful family of 

 unicellular Algce. Good examples 

 of stellate cells are also afforded 

 by the stems of the Common 

 Rush (Juncus effusus, fig. 46), as 

 FIG. 44. STAR-SHAPED CELLS OF COMMON BEAN, well as by the Flowering Rush 



(Butomus wntbellatus), whose hand- 

 some rose-coloured flowers, rising above the 

 surface of the water on a stalk three or four 

 feet high, make it deservedly a favourite 

 with lovers of British water-plants (fig. 51). 

 Of more than morphological import- 

 ance are the facts to be next noticed. 

 "Endlessly diversified in the details of 

 their form and structure," says Professor 

 E. B. Wilson in his fine work on the vege- 

 table cells, "these protoplasmic masses 

 nevertheless possess a characteristic type 

 of organism common to them all ; hence 

 in a certain sense they may be regarded 

 as elementary organic units out of which 

 the body is compounded. The composite 



FIG. 46. STAB-SHAPED CELLS FROM STEM OF 

 COMMON RUSH. 



FIG. 45. A DESMID. 



One of the simplest forms of green plants. 



structure is, however, character- 

 istic of only the higher forms of 

 life. Among the lowest forms 

 at the base of the series are an 

 immense number of microscopic 

 plants and animals, familiar ex- 

 amples of which are the Bacteria, 

 Diatoms (fig. 49), Rhizopods, and 

 Infusoria, in which the entire 

 body consists of a single cell, of 

 the same general type as those 

 which in the higher multicellular 

 forms are associated to form one 

 organic whole. Structurally, 

 therefore, the multicellular body 

 is in a certain sense comparable 

 with a colony or aggregation of 



