SPECIAL NUCLEAR PHENOMENA. 5! 



initiated in recent years, in both animals and plants, that the ciliary 

 apparatus of the male cell arises from a more or less modified central 

 body, is strong ground for the acceptance of this view. Further, the 

 process of transformation of the polar aster into an ellipsoidal mem- 

 brane is to be compared with other cases of intra-cytoplasmic migra- 

 tions, such as those of the central spindle fibers in building the cell 

 plate and the migrations of the asters of the sperm cell in the animal 

 egg in the processes of fertilization. Though the resemblances in all 

 these processes are not yet clear, we certainly have sufficient ground for 

 assuming that the fibrous material concerned in them all constitutes a 

 specially differentiated material of the cell the kinoplasm. 



That the spore as at first formed has no cellulose wall is well shown 

 in cases in which it is plasmolyzed in fixation. In such cases the sepa- 

 ration of the spore-plasm from the epiplasm is complete and there is 

 no trace of a cell-wall in the cleft so formed. The surface of the plas- 

 molyzed spore shows the same continuity as we find in the surface of 

 the protoplast of the ascus, and there can be no doubt that the spore 

 boundary formed by the fibers of the polar aster, even at this early stage, 

 is essentially similar in its nature to the layer bounding the entire ascus 

 or other cells of the mycelium. 



Whether the material of the fibers has undergone a chemical change 

 in forming this continuous membranous layer is difficult to determine. 

 That their staining reactions change somewhat seems fairly evident in 

 most cases. As fibers of the polar aster they take the blue color in the 

 triple stain. On the surface of the completely delimited spore it is 

 difficult, if not impossible, to distinguish a layer differently stained 

 from the spore-plasm which it surrounds. Still occasionally, in the 

 triple stain, this layer does show a bluish-gray tint somewhat clearly 

 differentiated from the gray or faint orange of the inner spore-plasm. 

 If, as Overton (73, 74) concludes, the outer layer of the protoplast is 

 a cholesterin-like substance or is impregnated with such a substance, 

 it must probably be assumed that the kinoplasmic fibers undergo a 

 decomposition in forming the limiting layer of the spore. On the other 

 hand, the fact that these fibers maintain their identity and do not mingle 

 with or dissolve in the cytoplasm about them while they form the polar 

 aster is sufficient evidence that their substance is capable, without chem- 

 ical change, of forming an osmotic layer sufficiently differentiated to 

 separate the spore-plasm from the remaining cytoplasm, at least to an 

 extent which would permit the plasmolyzing of the spore mass. 



In the case of these preparations with shrunken spores we can make 

 out, by careful observation, in some cases, an interesting difference 



