434 The Systematic Value of the Nezu Species. 



LENGTH OF THE CALYX-TUBE. 



Millimeters O. miiricata O. bie?inis 



Number of flowers 58 101 25 



Large numbers of such tables could be made ; and the 

 result would be well worth the labor if they demon- 

 strated, as they most certainly would, that the universal- 

 ity of the law of transgressive variability is no argu- 

 ment against the independence and immutability of spe- 

 cies. 



Let us now examine a second group of characters, 

 namely those which do not separate related species or at 

 any rate only to a very slight extent. In this case the 

 mean values will either coincide or show slight differ- 

 ences caused by external conditions. For example I found 



