588 GEORGE H. BISHOP 



characteristic of such a condition as long as this state of the 

 membrane obtains; The first evidence of a change in the nucleus 

 appears as a slight modification in the condition of this phase 

 difTerence — a modification which is noticeable microscopically 

 as a slight thickening, a more cloudy staining, and less sharp 

 definition. This takes place even before the fat-globules reach 

 the nuclear region (stage of fig. 3, pi. 1). As the process goes 

 further, the membrane may finally be completely dissipated, and 

 no residue left that can be distinguished as the material of which 

 it was composed. The border-ground between nucleus and cyto- 

 plasm then grades imperceptibly from one to the other, staining 

 only a little more densely where the two materials appear to 

 diffuse; as if each retained its intrinsic staining capacity, and 

 the resulting stain was an additive effect of the characterisic 

 staining of both. This border-ground now appears to offer no 

 resistance to the passage of the basophile granules, which are 

 found indiscriminately on either side and within the region 

 where the two materials are diffused (pi. 1, figs. 5, 6, 7). 



Along the sides of the nucleus it is exceedingly difficult to 

 discern just what the state of the border is, for here the central 

 fat vacuoles which indent the nucleus complicate the picture. 

 The surfaces of these vacuoles (or more accurately', the surface 

 of the material surrounding the vacuoles) stain more sharply 

 and more densely than the surfaces of vacuoles situated more 

 peripherally in the cells ; and since these surfaces lose their sharp 

 staining capacity as the vacuoles disperse throughout the cyto- 

 plasm, it may be inferred that they are enveloped by a film con- 

 sisting of a mixture of the nuclear sap and cytoplasm, and 

 that the staining of this film is in reality a stain of the same 

 nucleus-cytoplasm complex as was the staining of the nuclear 

 membrane itself.^ The conditions causing a phase membrane 

 to disintegrate from the nucleus-cytoplasm surface might affect 

 the surface of the fat-vacuoles more tardily, and these might still 



2 This supposition is of course somewhat hypothetical. Different proteins, in 

 colloid form, are affected differently by changes of acidity, some becoming more 

 and some less hj-drophilic. A change in acidity of one or another in turn would 

 cause a change in the respective viscosities, which might be conceived to result in 

 membrane formation and other complicated physical phenomena, even such as 



