580 Chas. W. Hargitt. 



due in some measure to the artificial conditions under which 

 they were reared, led me to anticipate similar results in ephyrae 

 obtained from an environment like the "eel pond." In this, 

 however, I was somewhat disappointed. For while the ratio of 

 variation found was somewhat larger than that in either of the 

 series from Waquoit, as will be seen by a comparison of the tables, 

 still it was far less than had been anticipated. The total number 

 found among the 486 specimens taken in the eel pond which 

 showed variant features was 144, or 29.6 per cent. 



In the collections from Waquoit the series of 1901 comprising 

 1026 specimens the variants were 24.9 per cent; of the series of 

 1904, the 218 ephyrae showed 22.9 per cent of variants. 



While the difference in favor of the eel pond series is appreciable, 

 it is still small, too small indeed, to warrant a final conclusion as 

 to the influence of any given factor as a determining condition. 

 Again, it must not be overlooked that the number of specimens 

 under consideration was likewise comparatively small. 



Moreover, when we come to compare the data obtained relative 

 to series of adults the uncertainty is greatly accentuated. Com- 

 paring the data of Table VI with those of Table VII, wherein are 

 shown the several features of variation, it will be seen that those 

 from the New Bedford environment, within which they were 

 doubtless bred and reared, have a lower per cent than those from 

 Waquoit, the exact figures of the two being 22.5 per cent for the 

 former, and 24.3 per cent for the latter. 



Therefore when a careful analysis of the available data is made 

 we are compelled to admit that the evidence concerning the 

 influence of environment so far as the present organisms are con- 

 cerned is not convincing. And until further and more extended 

 comparisons can be made in these or similar circumstances the 

 answer to the general problem must be regarded as negative. 



SIGNIFICANCE OF THE VARIATIONS IN RELATION TO NATURAL 



SELECTION. 



From the foregoing review of the history of variation as it 

 pertains to Aurelia in particular, and to a less extent to other 

 Scyphomedusae also, it must be quite evident that the phenomena 

 are numerous and involve almost every part of the organism. 

 Furthermore, so far as Aurelia is concerned, variations have been 



