144 



THE PLANT-LIKE 



was so long a strong basis, and apparently invincible, namely, that 

 vibratile cilia are indubitable indications of an animal nature in 

 the body which possesses them, for we have seen how active 

 those cilia are which are attached to the spores of the lowly 

 organized plants. They also said that the red " eye-spot " as 

 Ehrenberg believed it to be, and consequently deemed it a nerve 

 of sense, had also lost character, and was reduced to a mere 

 globule of oily matter which was sometimes present in, and 

 sometimes absent from, the rapidly changing contents of the 

 flitting, spasmodic spores. It is true, however, that certain un- 

 doubted animals, Euglena (fig. 86) for instance, also have this 

 red, eye-like spot; but its presence in spores of plants deprives 

 it of all character as a mark of distinction unless accompanied 

 by other diagnostic features. 



Casting about from point to point, endeavoring to find some 

 safe foundation upon which to raise a firmer and more lasting 

 framework, naturalists came to the conclusion to settle down 

 upon contractility as one reliable character, and the absorption 

 of food as another, and probably the more trustworthy; but both 

 were far beyond suspicion, as was then thought. 



Let us see, now, what proofs of animality we 

 may derive from some of the infusoria which most 

 resemble the sea-weed-spores. I will take, for ex- 

 ample, one of the most familiar and common of the 

 animalcules ; it is known under the name of Euglena, or 

 the Eye-animalcule, (fig. 86). The resemblance in char- 

 acter to the spore of Saprolegna is heightened by the 

 fact that the vibratile ciliurn (fig. 86, 1} of the Euglena, 

 like that of the former, emerges from a notch near the 

 narrower end, and moreover there is close to it a 

 nucleus-like spot ; but the latter in Euglena is red, and 

 is known as the red eye-spot (e). The spores of 

 Cladophora (fig. 82) and Chorda (fig. 85), you will recol- 

 lect, also have a red spot near the vibratile lashes ; 



Fig. 86. Euglena spirogyra. Ehr. 300 diain. The Eye-animalcule, e, the 

 red eye-spot ; I, the vibratory lash. Original. 



