378 THE BEGINNINGS OF LIFE. 



to observe what became of these bodies, I carefully 

 watched one for some hours, and observed the follow- 

 ing: First, the movement by protrusion became gradu- 

 ally restricted till it was extinguished, the mass returning 

 to the ovoid form it possessed originally. The exterior 

 also seemed to become more rigid, although I do not 

 think there was any distinct cell-wall. Secondly, the 

 whole exterior became covered with very minute cilia in 

 constant vibration, by which the mass was kept in a 

 state of agitation within the containing cell. The total 

 motion was curtailed, of course but in bodies which I 

 noticed moving in the water undistinguishable from 

 them, the motion was rapid and rolling. Beyond this 

 point I was unable to extend my observations on their 

 life -history/ This change from the amoeboid to the 

 ciliated state was rapidly effected, since Dr. Hicks had 

 seen it brought about in the course of two hours '. 



We will now refer to some observations, previously 

 alluded, to and made by Mr. H. J. Carter, which also 

 furnish us with particulars of the greatest interest. 



At pp. 187-190 of vol. i. we described the early changes 

 taking place within an internode of a Nitella which is 

 about to die. We then quoted Mr. Carter's description 

 of the mode of formation of the c gonidial' cell, as 

 he at that time called it, and have now to follow his 



1 Dr. Gros had, however, long before and even anterior to the date of 

 Pringsheim's observations declared that the nuclei of the spiral bands 

 of Spirogyra might individualize themselves and become converted into 

 Monads which, subsequently developed into different forms of Ciliated 

 Infusoria. (See ' Bullet, de la Soc. de Nat. de Moscou/ 1851, p. 477.) 



