1899] AT LAST? 91 



Conidia of the mould Aspergillus niger were cultivated (A) in a 

 Eaulin solution, (B) in a Eaulin solution plus 6 per cent of common 

 salt for one generation, and (C) in the same for two generations. 



Then they were placed in a Eaulin solution plus 18 - 4 per cent of 

 salt, in which A showed no germination, B slight germination, and C 

 general germination ; again, in a Eaulin solution plus G per cent of 

 salt, in which A produced spores in 5 days, B in 4 days, and C in 3J 

 days ; and again, in a Eaulin solution without additional salt, in which 

 A showed sporification in 4 days, B in 5 days, C in 5 days, but 

 slight. 



Spores from the last-named three cultures, in a normal Eaulin 

 solution, were then sowed in Eaulin solution plus 18*4 per cent of 

 salt, in which A' showed after 5 days no germination ; B', after 5 

 days, just visible germination ; and C/, after 5 days, clearly visible 

 germination. 



Hence, it is argued, that the conidia of Aspergillus become adapted 

 to the medium in which their parent is growing, and more adapted 

 after the second generation than after the first ; and, as the adaptation 

 to a concentrated medium is not wholly lost after rearing in a normal 

 medium, there is evidently a persistence of the adaptation, an inherit- 

 ance of the acquired quality of resistance to concentration. 



In truth, however, this is not very convincing. The distinction 

 between soma and germ-cells is not more than incipient in the mould 

 in question ; and even if it were more marked, what does the case 

 show but that the germ-plasm may be affected along with the soma 

 by a saturating influence, which nobody can deny. 



We need more than this before we allege the inheritance of an 

 acquired character. We wish to hear of a clear-cut somatic modifica- 

 tion observed to occur in successive generations, and of the recurrence 

 of this modification or of some change in the same direction in the 

 offspring when these are reared in a environment from which the 

 original cause or stimulus of the modification is absent. At the best, 

 Errera's case is no more cogent than those which have been adduced 

 from the study of alcoholism, where the germ-cells are apparently 

 affected along with the body — cases with which Weismann has duly 

 dealt. 



We may, however, recall David Harum's words : " A reasonable 

 amount of fleas is good for a dog — they keep him f'm broodin' on 

 bein' a dog ; " and re-interpret them, saying that a reasonable amount 

 of such experiments as those of Errera is good for Weismannists — if 

 so be they keep them from brooding on the perfection of their 

 system. 



