PROPERTIES OF PROTOPLASM 



139 



of alkalis also, but whether true or not, the effect of alkalis on the 

 swelling of gelatine is greater at low concentrations than that of acids. 

 In the case of the protoplasm however a higher concentration of alkali 

 was required than of acid. 



The following conclusions may be advanced for further considera- 

 tion and experiment. 



The living protoplasm as such behav^es towards acids and alkalis 

 in a manner sufficiently like that of gelatine to warrant the view that 

 imbibition is a factor in growth. That the results in growth are 

 called forth by much lower concentrations of the reagents used than 

 can produce an analogous effect on gelatine is probably due to the 

 different nature of the emulsoids involved. 



lO % £aTre 



Figure 1.— Graphs of the growth rates of the pollen tubes of the sweet pea 

 (Lathyrus odoratus) in various concentrations of cane sugar, in 2Q% cane sugar 

 combined with sodium hydrate and in 40% cane sugar combined with acetic acid. 



