Experimental Pedigree-Cultures 555 



tion, partly no doubt to chance, even more mu- 

 tants were found this year than in the former. 

 Out of some 8000 seedlings I counted 377 deviat- 

 ing ones, or nearly 5^, which is a high propor- 

 tion. Most of them were oblonga and lata, the 

 same types that had constituted the majority in 

 the former year. 



Alhida, nanella and ruhrinervis appeared in 

 large numbers, and even scintillans, of which 

 I had but a single plant in the previous genera- 

 tion, was repeated sixfold. 



New forms did not arise, and the capacity of 

 my strain seemed exhausted. This conclusion 

 was strengthened by the results of the next 

 three generations, which were made on a much 

 smaller scale and yielded the same, or at least 

 the mutants most commonly seen in previous 

 years. 



Instead of giving the figures for these last 

 two years separately, I will now summarize my 

 whole experiment in the form of a pedigree. In 

 this the normal lamarckiana was the main line, 

 and seeds were only sown from plants after suf- 

 ficient isolation either of the plants themselves, 

 or in the latter years by means of paper bags 

 enclosing the inflorescences. I have given the 

 number of seedlings of lamarckiana which were 

 examined each year in the table below. Of 

 course by far the largest number of them were 



