306 



BOTANICAL GAZETTE 



[OCTOBER 



40.2 per cent and 24.2 per cent. Transfer to the sugar solution 

 caused an average shrinkage back to 7 . 2 per cent elongation. 



In the extreme individuals the shrinkage was back to 17.5 per 

 cent and 7.7 per cent elongation. It is evident that permanent 

 elongation or growth has set in to a slight but measurable degree 

 at the end of 5 hours. In one of the extreme individuals the growth 

 was considerable. This is another example of the great individual 



variation that is always evident. 



shows 



results 



the 



curves. 



Table 



shows the changes in 

 length brought about in 14 Alisma 

 embryos by soaking them 16 hours 



volume mol. cane sugar for 25 hours. 



Time 5 h 



10A 



35/* 



Fig. 6. — Percentage of elongation of Alisma embryos (seed coat removed at both 

 ends) soaked in water 5 hours, then placed in 2 mol. cane sugar solution: measure- 

 ments were made on dry embryos, after 5 hours in water, and after 5 and 30 hours in 

 the sugar solution; i, curve for the 8 embryos studied; i', curve for the individual 

 showing the greatest swelling; *", curve for the individual showing least swelling. 



while the sugar causes a shrinkage back to 



11 or 1 



2 per cent elonga- 



tion. The behavior of the extreme individuals is also shown in 

 this table. Greater permanent elongation is evident than in the 

 embryos in water for 5 hours. Here also there is some evidence of 

 a slight permeability to sugar as shown by a slight swelling from 5 

 hours to 10 hours. Fig. 7 shows these data in the form of curves. 



