Protoplasm Streaming 267 



produced in a very short time; the length of time maintainable and the 

 various conditions surrounding complete recovery without plasmolysis 

 being produced. These remarks apply not only to very young but also 

 to older specimens where streaming is observable. The sudden transfer 

 from solutions of different concentrations below the plasmolytic strength 

 is also in need of study. In one other set of experiments sudden plas- 

 molysis was produced by a 40 per cent solution of cane sugar and in 

 15 seconds streaming ceased. In this case the protoplasm was plasmo- 

 lysed into several parts. However, at the expiration of 21 hours the 

 filaments all presented the normal appearance of the controls and were 

 streaming actively but somewhat less rapidly than at first. In certain 

 filaments of Rhizopus a comparative study of hyptogen membranes con- 

 stitutes a topic of special interest. 



Experiments with glycerine of 25 per cent, as expected, allowed no 

 growth. In 12% per cent glycerine seven spores in each 100 germinated. 

 In 6 per cent 30 spores in 100 grew and in 3 per cent glycerine 82 in 

 each 100 germinated and grew well. 



Potassium nitrate having a strength of 2 per cent permitted a germi- 

 nation of 37 spores for each 100. Above this strength growth and stream- 

 ing soon ceased. Above isosmotic valuations growth and streaming 

 were feeble or ceased altogether.' The specimens plasmolysed by po- 

 tassium nitrate lived a much shorter time than those plasmolysed by 

 cane sugar. 



' Eschenhagen. Einfluss von Losungen verscheidener Concentration Auf Schim- 

 melpilze, 1889, p. 55. 



