4 G. L. KITE. 



Particularly striking permeability phenomena are to be ob- 

 served when dyes that do not penetrate Ameba protects are in- 

 jected into the interior. Azolitmin, congo red, tropeolin ooo 

 No. i, sodium alizarin sulphonate, and indigo-carmin were used 

 for these injections. 



All the dyes enumerated were dissolved in salt and sugar 

 solutions of different concentrations, and small and large doses 

 were injected. It was found that these dyes diffuse quickly 

 through the interior of A. proteus, if the concentration of the 

 salt or sugar solution be not too high. A localized blue vacuole 

 results when indigo-carmin, dissolved in distilled water, is in- 

 jected into the ectoplasm of this animal. Usually in a short time 

 the vacuole breaks into the interior and the dye rapidly diffuses. 



Sea water, distilled water, solutions of sodium chloride, po- 

 tassium nitrate, and cane sugar have been injected into the 

 interior of different types of cells. A small dose of distilled 

 water is taken up by the surrounding cytoplasm of the starfish 

 egg quite slowly. A vacuole of sea water requires a somewhat 

 longer time to disappear, while a vacuole filled with hypertonic 

 sea water increases in size. Hence, any portion of the cytoplasm 

 of the starfish egg can exhibit the same general diosmotic proper- 

 ties that are shown by the surface. It seems that this is also 

 true for the cytoplasm of the striped muscle cell of Necturus, but 

 on account of the very high viscosity of this substance the wall 

 surrounding the injected fluid remains very irregular, and no 

 accurate measurement of the volume injected could be made. 

 Distilled water is absorbed from the interior of the muscle 

 substance extremely slowly; and salt and sugar solutions more 

 slowly or not at all. 



Doses of i m. sodium chloride and potassium nitrate and from 

 .5 M. to 2 M. cane sugar diffuse through the cytoplasm of Ameba 

 proteus when injected into the interior. The vacuoles that are 

 formed by the injected fluid quickly collapse. Granules, fibrils, 

 and globules can be produced in proteus by the injection of 2 M. 

 cane sugar. The shrunken part of the cytoplasm does not readily 

 take up water again. 



In this connection it may be added that the injection of mer- 

 curv and isotonic salt solutions and the introduction of various 



