- U.- 



The st-culy of the elaioplasts in these species was ijnciertalaen by me 

 from the micro chemical standpoint and from the Tnorr-liological and biological 

 points of view, and I hope my observations may complete the contributions 

 reported in preceding papers. 



Method ; In the study of the plasmatic stroma of the organ in question 

 I have used as fixative solutions an alcoholic solution of corrosive sublimate j. 

 alcoholic solution of picric acad, and a solution of absolute alcohol containing 

 5 per cent of acetic acid. 



In the monochromatic staining I have maule use of fuohsine, eosine, 

 aurantine and erythrosine, and later have preferably used Zjamnermann's mixture 

 (iodine green and fuchsine). 



With these reagents I was able to demonstrate that the stroma is 

 eminently erythrcse and neas-ly alw^s presents an affinity for stains similar 

 to that of the nucleolus. 



In the study of the distribution of the elaioplasts in diverse parts 

 of the single species, I availed myself almost exclusively of fresh material, 

 since these bodies because of their strong refractility and the characteristic 

 forms which they present are easily recognizable, and it would, I believe, be 

 unnecessary to have recourse to special stains. However, in those cases in 

 which the elaioplasts might be confused with the nucleus or with other bodies 

 included in the cytoplasm I used osmic acid, a solution of potassium iodide, 

 Sudan III> and Scarlet E. 



With the first of these reagents, employed also by Zimmermann, the 

 elaioplasts in a few minutes turned brown or blackish. 



With the second of these reagents, the starch granules took on, ac- 

 cording to the length of time the reagent was allowed to act, a violet color 

 or azure blue more or leas intense. The protoplasm stained a golden brown, 



