39O DALTON G. PAXMAN. 



nuclear granules are fundamentally the same as the remaining 

 protoplasm of the cell, but are differentiated therefrom under 

 physiological conditions which we do not at present understand; 

 that the granules are perhaps reserve material stored up in the 

 nucleus for future use, the entire cell body being thus occasionally 

 converted into a nucleus; and the nucleus varies in structure 

 from time to time in response to the varing physiological demands 

 made upon it. ... Further if my interpretation of my ob- 

 servations be correct, then distinction between germ and somatic 

 plasm is obviously impossible, a special vehicle for the trans- 

 ference of hereditary qualities is entirely wanting; such qualities 

 must be transmitted by the undifferentiated protoplasm; cell 

 lineage is manifestly lacking; a mosaic theory is plainly untenable; 

 and the fate of any given embryonic element whether it shall 

 form parenchyma, muscle, nerve, etc. must be determined by 

 physiological causes alone." 



Richards (1911), working with Moniezia, does not agree with 

 Child. He says (p. 158): "I have after diligent search upon 

 carefully prepared material been unable to establish a series of 

 stages in the autoconstriction and subsequent division of the 

 nucleus and cell body by amitosis. Considering the evidence as 

 set forth, it seems to the writer that one is forced to the con- 

 clusion that mitosis is the method by which pre-oogonia and 

 cleavage divisions are accomplished." 



Mary T. Harman ('13, p. 223) states: "My observations have 

 not shown that amitosis does not take place in Taenia or Moniezia, 

 but they have show r n no condition which cannot be as readily 

 explained as the result of mitotic as of amitotic division." 



MATERIALS AND PROCEDURE. 



The form I worked with was Dilepis scolecina parasitic in the 

 small intestine of the double-crested cormorant (Phalocrocorax 

 dilophus). These birds are found abundantly near the shores 

 and on the islands of Devils Lake, North Dakota. 



Immediately after the bird was killed, the cestodes were 

 removed from the intestine and placed in fixing solution. Flem- 

 ming's solution and cestode mixture were the fixatives used. 

 Flemming's solution blackened the tissue so that the results 



