TKANSMISSION OP ACQUIRED CHARACTERS. 409 



But it was not always the case that the double flowers continued 

 to appear after they had been once produced. In Palaver alpimtm, 

 which Hoffman has cultivated in successive generations since 

 1862, other changes in addition to the doubling of the flowers first 

 appeared in 1882, viz. a slight variability in the form of the leaf, 

 and a greater variability in the colours of the flowers. The pro- 

 duction of double flowers appeared to be favoured by poor nutrition 

 caused by crowding the plants. The results as regards the number 

 of double flowers produced in this species by close sowing, from 

 1882-1886, have been as follows : 



Experiment XI. 1881. 40 per cent, of double flowers. 



1882. 4 



1883. 5.3 



Experiment XVII. 1884. 13- 



1885. o-o 



1886. o-o 



Although in these and some other series of generations the 

 double flowers again disappeared in the later generations, yet there 

 can be hardly any doubt that their first appearance was due to the 

 abnormal conditions of nutrition. This conclusion is also unaffected 

 by the fact that double flowers appeared in nearly the same pro- 

 portions in consequence of cultivation in ordinary garden soil. The 

 plants which were crowded in pots produced 2879 normal flowers, 

 and 256 (=8-8 per cent.) abnormal and mostly double ones, while 

 867 normal and 62 ( = 7-0 per cent.) abnormal ones were produced 

 on garden beds. Hoffman will not indeed admit that such a 

 comparison can be fairly made, for the plants in the garden beds 

 were raised from seed which was in part taken from the double 

 flowers, and was therefore, he believed, under a strong hereditary 

 influence. But this latter assumption is not supported by the 

 results of his own experiments. 



Thus experiment XVIII., conducted upon Papaver alpinum, is 

 described in these words, ' Seeds yielded by double flowers from 

 experiment XI. (1883), were sown in pots, and the resulting plants 

 produced from 1884-1886, fifty-three single flowers and no double 

 ones.' 



Hoffmann speaks are hereditary, the term cannot be rightly applied to them, and 

 I shall prove later on that they cannot be regarded as acquired characters in the 

 sense required by the theory of descent. 



