POLARITY AND BILATERALITV OF THE ANNELID EGG. 79 



nucleus and granules are undetermined by these experiments ; 

 but their importance in the physiology of development is not open 

 to question. 



LITERATURE. 

 Lillie, Frank R. 



'06 Observations and Experiments Concerning the Elementary Phenomena of 



Embryonic Development in Ch?etopterus. Journ. Exp. Zool., III., 1906. 

 '08 On the Specific Gravity of Constituent Parts of the Egg of Chretopterus and 

 the Effect of Centrifuging on the Polarity of the Egg. Abstract, Science, N. 

 S., Vol. XXVII., June, 1908. 



'08 A Contribution Towards an Experimental Analysis of the Karyokinetic Figure. 

 Abstract, Science, N. S., Vol. XXVII. , June, 1908. 



Lyon, E. P. 



'05-6 Some Results of Centrifuging the Eggs of Arbacia. Amer. Journ. Phys., 

 Vol. XV., 1905-1906. 



Morgan, T. H., and Lyon, E. P. 



'07 The Relation of Substances of the Egg, Separated by a Strong Centrifugal 

 Force, to the Location of the Embryo. Arch. Entw'mech., XXIV., July, 

 1907. 

 Morgan, T. H. 



'08 The Location of Embryo-forming Regions in the Egg. Science, N. S., 

 August, 1908. 



Lehmann, 0. 

 '08 Scheinbar lebende Krystalle, Pseudopodien, Cilien und Muskeln. Biol. 



Centralblatt, Bd. XXVIII., Aug., 1908. 

 '04 Fliissige Krystallen. Leipzig, Wilhelm Englemann, 1904. 



