436 PRIMARY FACTORS OF ORGANIC EVOLUTION. 



flock, the same individual animals, when pastured at 

 two stations. The first were shorn when the sheep 

 were pastured in southeastern Ohio, where the sheep 

 were bred, a region noted for certain excellencies of 

 its wool. Taken to a certain portion of Texas, and 

 pastured on an alkaline soil, the wool of those sheep 

 took another character, affecting both its texture and 

 also its behavior with dyes. Treated in the same vats, 

 as to dye, lac and mordant, the difference is very ob- 

 vious. 



"A certain harshness of the wools produced in 

 some regions where the soil is alkaline or salt, the 

 climate dry, and the forage plants characteristic of 

 such regions, is widely known and is considered a de- 

 fect by manufacturers. It is stated that when a flock 

 is taken from a favorable region to such a less favor- 

 able one the change in the character of the wool begins 

 immediately, but is more marked in the succeeding 

 fleeces than in the first. It is also alleged that the 

 harshness increases with succeeding generations, and 

 that the flocks which have inhabited such regions sev- 

 eral generations produce naturally a harsher wool than 

 did their ancestors, or do the new-comers. 



"Now, in this case, the deterioration in successive 

 generations cannot possibly be due to panmixia, the 

 withdrawal of selection ; on the contrary, selection 

 goes on under the new conditions just as carefully as 

 under the old, and often more so, for this is the means 

 used to lessen the evil. 



1 ' If this increase in the harshness of the wool of 

 succeeding generations is due in part to the inheri- 

 tance of an acquired character, it is very understand- 

 able. That it is a congenital adventitious variation 



