124 



AQUATIC MICROSCOPY FOR BEGINNERS. 



Fig. 97.— DifRiigia 

 pyrif6rmis. 



Fig.98 — Difflugia coi6na. 



When the patch appeared on the ad- 

 vanced extremity, the Amoeba at once 

 began to move in the opposite di- 

 rection. It seemed as if the creature 

 considered the velvety spot as a clus- 

 ter of enimies to be 

 avoided. 



After becoming 

 densely villous over 

 the entire body it 

 rested for a few 

 minutes, when it 

 resumed its motions 

 and wandered about 

 the field of the mi- 

 croscope, becoming quiescent at intervals, until I was 

 compelled to leave it. On my return it was dead. Its 

 exit from the shell was, as I should reason from this, 

 caused by some discomfort or by some cause impossi- 

 ble for a human being to discover. 



Although this is the usual cause of such conduct. 

 Dr. G. C. Wallich reports that he has seen the common 

 Amoeba explore the mouth of an old and abandoned 

 shell of Difflugia, much, I suppose as the hermit- 

 crab will examine an apparently acceptable sea-shell 

 before leaping into it, and Dr. Wallich also states that 

 the Amoeba finally approved of the domicile as a home 

 and entering took possession, thenceforth protruding 

 its pseudopodia, and dragging the shell about, as if it 

 had been originally formed by its new occupant. 



The pseudopodia are blunt and colorless. They 

 drag the shell about with the mouth directly downward, 



