UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 18, No. 1, pp. 1-26, plate 1 October 16, 1917 



MITOSIS IN GIARDIA MICROTI /^^^ 



U OCT 30 1917 



WILLIAM C. BOECK \ Al^, ' ^^'S!^^^ 



CONTENTS 



PAGE 



Introduction 1 



Material and technique 2 



Table of infection 3 



Morphology 4 



Parabasal bodies 8 



Mitosis 11 



Prophase 11 



Metaphase 16 



Anaphase 16 



Telophase 17 



Correlations of mitosis with cytoplasmic structures and changes 18 



Neuromotor apparatus 19 



Cysts 20 



Conclusions 22 



Literature cited 24 



Explanation of plates 25 



Introducton 



The investigations of Kofoid and Christiansen (1915&) on Giardia 

 muris showed that multiple and binary fission were carried on in the 

 free state of the flagellates as well as during encystment, contrary to 

 the conclusion of Wenyon (1907), Prowazek and Werner (1914) and 

 others. Previous to this work, no evidence had been discovered for 

 the occurrence of multiple fission either in the free state or during 

 encystment. While the investigations on Giardia muris were being 

 carried on, a new species, Giardia microti, was discovered in the mea- 

 dow mouse, Microtus calif ornicus caUfornicus (Peale). 



In order to affirm further the work of Kofoid and Christiansen 

 with regard to binary fission occurring in the free state of the flagellate 

 and also to set forth the process of mitosis, investigations were made 

 upon this new species, Giardia microti. 



