Munson, Organization and Polarity of Protoplasm. 373 



of these cilia, causing a steady progression, must involve some 

 definite protoplasmic areas within the cell, which cause the move- 

 ments. A coordination by morphological continuity of proto- 

 plasmic fibers is clearly suggested. 



If it be urged that this is an infusorian, and therefore a 

 highly developed cell, it may be answered, that the mere fact 

 of its being a single cell, instead of an aggregation of cells, ought- 

 not to justify us in denying, on „apriori" grounds, all Organi- 

 zation, where so many evidences of Organization exist. If we 

 deny Organization in the cell, why speak of one cell as being higher 

 than another? What does this „high" or „low" mean if it does 

 not refer to grades of Organization? 



II. 

 Internal Evidences of Polarity. 



The animal ovum. A section of the ovarian egg of Li- 

 mulus is represented in fig. 5, pl. Ic. The germinal vesicle, in this 

 particular egg, is seen to be amoeboid, and contracted; but other- 

 wise normal, showing perfect fixation. It contains a large, hol- 

 low nucleolus, open at one end, and filled with a granulär sub- 

 stance, not unlike the caryolymph, in which the crowded nuclear 

 reticulum lies imbedded. Surrounding the germinal vesicle, and 

 occupying the invaginated wall of the nuclear membrane, is a 

 granulär substance, which, from its relation to the nucleus, Seems 

 to have been forced out from the nucleus. In this particular in- 

 stance, it is more granulär than the caryolymph and stains diffe- 

 rently. But in many cases this is seen to be a clear substance 

 resembling the caryolymph. 



I have already expressed elsewhere 1 ) that this substance in 

 the neighbourhood of the nucleus is in fact extruded caryolymph, 

 which on Coming in contact with substances in the cytoplasm, 

 unites with this forming a new substance which stains differently 

 from both the nuclear chromatin and the caryolymph. 



From the study of dividing cells, it is clear that the caryo- 

 tymph is secreted in the chromatin substance, and in the case 

 represented in fig. 5, pl. Ic, the large nucleolus is essentially an 

 aggregation of chromatin. The case, therefore, seems to be this: 

 the caryolymph is produced at the expense of the chromatin. It 

 is periodically extruded from the nucleolus; and, at first, has the 

 characteristics of caryolymph. But on contact with proteid sub- 

 stances in the cytoplasm, these are split up and new Compounds 

 are formed, which behave differently toward stains than either 



*) Munson: The Ovarion Egg of Lz'mulus, a Contribution to the problem 

 of the centrosome and yolk-nucleus. (Journal of Morphology, no. 2, Vol. XV, li 



