INDUCED CHARACTERS IN ASPLANCHNA AMPHORA 377 



saved and from it was reared a series which we term J 2' . Another 

 series of similar derivation was reared from a resting egg produced 

 by the third individual of the fifty-fourth generation, fertilized by 

 a male, a brother to the one used to fertilize the mother of the 

 preceding series. The series was begun by isolating the individual 

 on March 24. We term this series J 2". The history of the fifteen 

 series oil 3, together with the contrasting series J 2' and J 2" , is 

 given in table 3. 



The study of table 3 shows again the surprising fact — the com- 

 plete hereditary continuence through the resting egg of the di- 

 verse qualities originally induced in the two contrasting stocks. 

 Throughout the entire ten generations through which the fifteen 

 series of 7 3 were carried, not a single instance of the transition 

 from the saccate type to the humped type occurred, although in a 

 few of numerous mass cultures derived from these saccate series 

 such transitions did occur, though sparingly. On the other hand, 

 despite uniform feeding and other parallel conditions, the lines 

 J 2' and J 2" again leapt almost immediately to the humped 

 form. This occurred in the second and third generation respec- 

 tively, and it is of no less significance that there was in each of 

 these series an almost immediate production, no doubt through 

 cannibalism, of the third or campanulate type. This shows still 

 more conclusively the inherent high potential so fully maintained 

 by this stock. 



Although no farther evidence was needed to test the single 

 matter of inherited potential through the resting egg, yet the 

 thought of the possibility of the formation of a saccate race 

 devoid of any mutational tendency induced us to develop still 

 more series. A culture derived from the fourth generation of 

 series 11 oi I 3 was allowed to mass. Males were produced by 

 saccate individuals on April 14 and resting eggs were duly formed 

 by saccate females. An individual, hatched from one of these, 

 gave the starting point of series 14- It was bred through thirteen 

 generations. Its history is given in table 4. Again the saccate 

 type was constant throughout the entire series. But in mass 

 cultures, which were now forced by special feeding to test at once 

 their character, it was still possible to induce the transformation 

 to the humped type. No campanulates were formed. 



THE JOURNAL OF EXPEMMENTAL ZOOLOGY, VOL. 16, NO. 3 



