THE BEGINNINGS OF LIFE. 513 



evenly-granular appearance, and none of them were larger 

 than 5^^" long by -^' broad {h). They differed, there- 

 fore, in the usual manner from the heterogenetic matrices 

 from which their parents had been derived ; and no 

 mistake could have occurred, since the gemmse were seen 

 and measured within the body of the parent as well as 

 after they had been laid, when the development of the 

 embryo within them was also watched (_/'). These gemmie 

 gave rise to organisms about the same size as those 

 which had proceeded from the encysted Vorticellic ^ 



Other observations made upon the contents of the 

 same vase were, however, even still more interesting, 

 since they have sufficed to reveal the heterogenetic 

 origin of one of the largest and best known of the 

 Rotifers. 



^ With reference to other direct heterogenetic modes of origin of 

 Rotifers, I may state that I have again and again seen small Rotifers 

 within the still-closed though dead internodes of Nitella, which I haA'e 

 every reason to believe were produced by the direct transformation of 

 some of the larger embryonal spheres that had been formed within the 

 filaments (see p. 401). The form of Rotifer most frequently seen under 

 these conditions was one with a shield-like carapace and single style, 

 apparently corresponding to the so-called Monostyla cornnta. Again, 

 quite recently, whilst engaged in the investigation of certain trans- 

 formations taking place in Vaucheria, I accidentally encountered a 

 number of young germinating spores, nearly every one of which, though 

 still green externally, contained a moving embryo Rotifer in its interior. 

 The spores were of the kind represented in Fig, 6, k, and they were only 

 very slightly more advanced in development. The diameter of the con- 

 tained embryo was about equal to one- half of the diameter of the spore- 

 I saw more than a dozen of these bodies, but unfortunately, owing to 

 my occupation with another series of transformations at the time, I did 

 not ascertain anything further concerning them. 



VOL. II. L 1 



