208 CORA J. BECKWITH 



the saffranin very intensely while the protoplasm is colored green. 

 The color of the granules differs, however, according to the 

 length of time the slide is left in the solution of light green, and 

 consequently to the degree of extraction of the saffranin, while 

 the chromatin stains in the same way under all circumstances. 

 For example, if the saffranin is but slightly extracted, the granules 

 are bright red like the chromatin, the protoplasm green. If the 

 saffranin is somewhat further extracted, the granules appear 

 purplish (i.e., a combination of the two colors), while the chroma- 

 tin remains bright red. If the extraction is more complete, the 

 granules become entirely green while the chromatin still appears 

 bright red. 



Since the above experiments suggested that the granules may 

 not respond to all chromatin-stains, further tests were made. 

 Several investigators (Crampton '96, Foot '96) have used solutions 

 of lithium carmine and Lyons blue to distinguish the yolk-nucleus 

 from the chromatin ; the yolk-nucleus is stained blue, the chromatin 

 stains with the carmine. Obviously, if the protoplasmic granules 

 in Hydractinia are chromatin, they should stain with carmine. 

 I find, however, that here again the granules stain differently 

 from the chromatin, since they take the blue stain and the nucleus 

 the red, this last even in late stages when the nucleus has usually 

 lost its affinity for basic dyes. Further differences between the 

 granules and the chromatin are shown by slight variations in their 

 staining reactions when iron-hematoxylin is used after different 

 killing fluids. As previously indicated, the granules are gray 

 after Meves' killing fluid, slightly darker after Flemming's fluid, 

 and intensely black after fixation in sublimate-acetic, formalin, 

 alcohol, and hot water. The staining tests on preserved material 

 indicate then, that the granules are not necessarily the same in 

 their reaction as chromatin. 



More striking and decisive results are given by experiments 

 with stains on fresh material (table 2). I first tried a dilute 

 solution of methyl-green slightly acidulated with acetic acid, as 

 recommended by Lee ('03) for a chromatin stain. Here the 

 results are as in the majority of experiments on fixed material, 

 i.e., the granules take the basic stain (methyl-green) strongly 



