Changes in Salinity and Effects on Regeneration , etc. 



89 



is seen that the curves for 105 to 75 per cent solutions are almost parallel. 



Beyond these limits the curves diverge. In the 75 to 55 per cent solutions 



there has been either an absolute or relatively greater increment than in 



the solutions approaching the norm. In the hypertonic solution there is 



no increase, the curves for the three periods are essentially parallel and 



overlap. 



Table 3. 



All these facts are made extremely clear after reducing some of the 

 irregularities of the curves, by grouping the results on a basis of 10 per cent 

 changes in salinity instead of 5 per cent, as shown in figure 2. 



Table 3 shows the results of table i grouped on a basis of 10 per cent 

 changes in salinity, instead of 5 per cent differences. 



In the preceding tables and curves the fact was ignored that in certain 

 solutions an arm was replaced by two arms. The supernumerary arms 

 appeared in the median solutions, viz, 1 1 1 to 85 per cent, with a few desul- 

 tory ones in more dilute solutions. The greatest number occurred in the 95 

 per cent solution, fewer in the 90 and 85 per cent, a sharp drop in 105 per 

 cent and iii per cent solutions, as shown in table 4. 



Table 4 gives the number of supernumerary arms in each solution and 

 shows that they tend to appear in optimum dilute solutions. 



Table 4. 



When the supernumerary arms are included in table i, it is found that 

 the highest part of the curve, 85 to 1 11 per cent, is augmented still further. 

 The maximum augmentation occurs in 85 to 95 per cent solutions, and only 

 a moderate increment occurs in sea-water. 



