TRANSMISSION OF ACQUIRED CHARACTERS. 407 



characters could hardly be doubted. I am not a botanist, but I 

 believe I am right in supposing* that the wild cherry reproduces 

 itself by seeds, while the edible domesticated cherry is propagated 

 by grafting. Grafts are, however, parts of the soma of a previously 

 existent tree, and we are not therefore concerned, in this method 

 of propagation, with a succession of generations, but with the suc- 

 cessive distribution of one and the same individual over many wild 

 stocks. But no one will doubt that one and the same individual 

 can be gradually changed during the course of its life, by the 

 direct action of external influences. The really doubtful point is 

 whether such changes can be transmitted by means of the germ- 

 cells. If, as I presume, the English in Ceylon do not care to eat 

 wild cherries but prefer the cultivated kinds, it follows that the 

 branches which bear fruit in that island have not been developed 

 from germ-cells, at any time since their introduction, and there is 

 nothing to prevent them from gradually changing their anatomical 

 and physiological characters in consequence of the direct influence 

 of climate. 



Hence the instance which Detmer looks upon as plainly con- 

 clusive, can hardly be accepted in support of such a far-reaching 

 assumption as the transmission of acquired characters. 



It is therefore clear that none of the facts brought forward by 

 Detmer really afford the proofs which he believes that they offer. 

 But another botanist, Professor Hoffman of Marburg, well known 

 for his long-continued experiments on variation, has recently called 

 attention to certain other botanical facts in support of the trans- 

 mission of acquired characters. These facts are indeed conclusive, 

 if we accept the author's use of the term ' acquired,' but it will 

 be found that they lead to hardly any modification in the state 

 of existing opinion upon the subject. 



. In a short note, dated Jan. I, 1888, the author communicated to 

 this journal (' Biologisches Centralblatt ') the statement that changes 

 in the structure of flowers caused by poor nutrition can be proved 

 to be hereditary to a greater or less extent 1 . 



A more elaborate account of the experiments will be found in 



several numbers of the 'Botanische Zeitung,' and the author 



expresses his final results in the following words (see Bot. Zeit. 



1887, p. 773) : 'These experiments prove with certainty (i) that 



1 Compare Biol. Centralbl. Bd. VII. No. 21. 



