22 Plant Genetics 



of numerous nurserymen, the only significant expen- 

 mental work being that of Engler of Zurich. Engler 

 (3) found that in the seedlings in his nursery growth 

 in height distinctly decreased as the altitude or latitude 

 from which the seed came increased. He also found 

 that seeds from pines which had been crippled by 

 growing in poor soil conditions gave rise to crippled 

 plants when grown in good soil. In many cases trees 

 of the third generation still showed the habit "acquired" 

 by their grandparents in different habitats. 



These are striking results, but they may be explained 

 in either of the two ways mentioned. Engler might 

 have been dealing with slightly different strains of 

 trees, differing in germinal constitution; or it may have 

 been another case of the "false inheritance of acquired 

 characters" that was explained in coimection with corn. 

 Seeds from higher latitudes and altitudes might well have 

 been smaller, so that we should have expected smaller 

 progeny, even when grown in the lowlands. 



A completely satisfactory investigation of the inherit- 

 ance of acquired characters in plants still remains to be 

 made. Seed from a single parent from a pure strain 

 should be planted in diverse conditions and the various 

 responses noted. Seed of the second and later genera- 

 tions of each lot should then be planted back in the 

 original conditions. If there should appear in this 

 generation even slight deviations from the original 

 type it would be significant, provided the deviations are 

 similar to those shown by the immediate parents in 

 each case and characteristic of the conditions under 

 which the parents grew. The peculiarities of progeny 

 due to Ught-weight seed should be tested by controls 



