482 THE BEGINNINGS OF IIFE. 



rapidly under a globular form, with its wall undulating 

 and cilia playing over it with corresponding activity. 

 . . . Occasionally, a sac might be seen under an elon- 

 gated, oblong form, with a slow undulatory change of 

 shape at one end, and a languid movement of the cilia 

 on its surface generally ; again it might be seen with 

 mucus-radii spread out in the same way as those of 

 Act'mophrys sol." Subsequently Mr. Carter tells us that 

 the almost endless modifications assumed by the sacs 

 were dependent upon their having been forced from 

 their cysts before they were developed. He afterwards 

 examined specimens very carefully which had been 

 liberated from the parent cysts in the natural way, and 

 then they were found to be veritable ciliated Infusoria 

 closely allied to Paramecium^ to which Mr. Carter gave 

 the generic name Otostoma, on account of the resem- 

 blance between the shape of the oral orifice and that 

 of the human ear. The segmentation of the protoplasm 

 within tlie parent sac is always into two, four, or eight 

 embryos; and these, when first liberated from the cyst, 

 present only one contracting vesicle. Subsequently 

 the mouth becomes more defined, and a second con- 

 tracting vesicle is produced ^ 



^ As in other instances, since the publication of these observations 

 Mr. Carter has endeavoured to put a different interpretation upon the 

 facts (see 'Ann. of Nat. Hist.' vol. viii. pp. 285 and 288). No feasible 

 explanations, however, are offered as to the means by which such large 

 Infusoria could have made their way into the closed chambers of the 

 Nitella, nor is it easy to believe that, after having got in, they would all 

 exhibit a gluttony so extreme as to account for the appearance of the 

 ciliated sacs as seen by Mr. Carter. Such a state of extreme engorgement 



