408 ON THE SUPPOSED BOTANICAL PROOFS OF THE 



insufficient nutrition may cause considerable morphological changes 

 (viz. qualitative variations) which are in the first place acquired 

 by thes exual apparatus of the flower, (2) that the "transient" (\\Yi 

 mann) characters acquired by the individual can be transmitted 1 .' 



The data upon which Hoffman bases these opinions are certain 

 experiments conducted upon various plants, in order to determine 

 the conditions of life under which abnormal flowers or any other 

 variations occur most frequently : to decide, in short, how far 

 variations are caused by the change of conditions. 



It is obvious that the attention of the author \vas not at first 

 directed to the question of the transmission of acquired characters. 

 His experiments are of a much older date than the present con- 

 dition and significance of the question before us. Hoffmann has, 

 in fact, re-examined his former results from the new point of view, 

 and this explains why his proofs are not always sufficiently con- 

 vincing when applied to the present issue. But this is of no 

 great importance, inasmuch as there is no necessity for me to 

 question the correctness of his assumptions. 



The essential details of the experiments to which he directs 

 attention are as follows. 



Different plants with normal flowers were subjected to greatly 

 changed conditions of life for a series of generations. They were, 

 for example, crowded together in small pots. Under these cir- 

 cumstances the plants were of course poorly nourished, and in the 

 course of generations, several species produced a variable proportion 

 of abnormal viz. double-flowers. This, however, was not always 

 the case, for such flowers did not appear in Hatthiola annua and 

 Heliantkemum polifolium. In other species, such as Nigella damas- 

 cena, Palaver alpinum and Tagetes patula, they appeared and often 

 increased in numbers in the course of generations, although this 

 was not a constant result. For instance, four successive genera- 

 tions of Nigella damascena, when closely sown, produced the 

 following results : 



1883. No double flowers. 



1884. 



1885. 23 typical flowers: 6 double flowers. 



1886. 10 ,, : i ,, flower. 



1 I have used the expression 'transient' ('passant') in the same sense as 

 ' acquired,' in order to enforce the conclusion that they are merely temporary, and 

 disappear with the individual in which they arise. Since the characters of which 



