302 



Uiiivcrsitjj of Califoniia Puhlications in Zoology [Vol. 2o 



eration sliould i-i'iirodiice in each instance which we have detected of 

 division in the supposed amoebae, the rhizopod type of mitosis. 



Through tlie courtesy of Dr. C. L. Ely of Stanford University 

 Medical School, unstained sections and undecalcified portions of the 

 excised head of the femur of liis case 187 of the second type (non- 

 bacterial) of arthritis deformans have been placed in our hands for 

 investigation. This excised bone had been iixed promptly in formalin 



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Kis;. \ 



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Fig. 1. Lateral view of a small epitlielioiil ( ? ) cell in the metapliase of 

 mitosis from a hypertrophied 'cervical gland of man in Hodgkin 's disease. Note 

 the absence of nuclear membrane, and the spindle fibers running from the eentro- 

 somes at the apices to the massed, deeply stained chromosomes in the equatorial 

 plate. From a section stained in iron liaematoxylin. X 2.500. 



Fig. 2. Lateral view of the anaphase of mitosis in a similar cell from the same 

 source. X 2.500. Note the elongated divided chi-omosomes retreating towards 

 the poles of the spindle, and the lateral constriction, indicating approaching sep- 

 aration of the two daughter cells. Only part of the chromosomes (about 16) of 

 the cell have been drawn, because of the superposition of the deeply stained rods 

 which form the chromosomes. We are indebted to Dr. Doxey Wilson and Dr. East- 

 man of San Jose for the material from which these sections were made. 



and was well preserved, thougfh difificult to stain, and somewhat difficult 

 to decolorize normally. The cells are splendidly preserved and the 

 tissiies came through decalcification with little if any disturbance. 



Prolonged and assiduous search among the amoeboid cells which 

 we interpreted as amoebae has brought to light several instances of 

 stages of mitosis and several binncleate amoebae, indicating that 

 asexual binary fission was in progress among the amoebae in the mar- 

 gins of the necrotic areas in the liead of the femur. 



