KARYOKINETIC FIGURES OF CENTR1FUGED EGGS. 117 



of the karyokinetic figure that, if the basophile granules are per- 

 meable to the force, (i) they would be oriented along the lines 

 of force when driven into the area of the karyokinetic figure ; (2) 

 that the number of rays in an unusually dense aggregation of 

 basophile particles would be greater than usual and (3) that the 

 number of oriented particles in each ray in such cases would be 

 greater than usual. 



These appear to be the conditions found in my experiments. 

 With reference to the first condition, there can be no question that 

 the basophile granules arrange themselves conformably to the 

 lines of the karyokinetic figure, as already noted. With reference 

 to the number of astral rays one obtains a strong subjective im- 

 pression that they are more numerous in the basophile cap than 

 in the asters of control eggs, and I have attempted to confirm this 

 by actual counts. To do this it is necessary to divide the aster 

 into sectors for comparison, for the reason that asters lying en- 

 tirely within the basophile cap do not occur, owing to the form 

 of the basophile cap. I have therefore made comparisons be- 

 tween sectors of 90 of the normal aster and asters of the baso- 

 phile cap. One has further to restrict the count by limiting it to 

 a single focus of the microscope. Under these conditions I 

 found an average of 8 rays to the 90 sector of the normal aster 

 (eighteen counts) and 12.5 in 90 sectors of asters in the baso- 

 phile cap (six counts). The difference seems too great to be ac- 

 counted for by error. The counts confirm the impression that 

 one receives by mere comparison. I do not think that such in- 

 crease of the number of rays in a sector of the aster could be 

 explained by compression of preexisting rays from other sectors 

 of the same aster, for they are quite uniformly spaced and are as 

 straight and regular as the normal rays. 



As regards the third condition : rays within the basophile cap 

 stain more strongly than those without ; but as the stain is held 

 by the granules, this would be evidence for a greater number of 

 granules in the rays. A ray that passes out of the basophile cap 

 loses suddenly in intensity of staining (Fig. 8). 



The spindle is decidedly denser than the surrounding proto- 

 plasm ; this has been noted by several investigators (cf. Foot 

 and Strobell (p. 221), and McClendon). The same thing is 



