March, 1908.] On the Cytology of Synchytrium. 283 



Literature. 

 Griggs, R. F. 



A Reducing Division in Ascaris. O. Nat. 6 : 519. 1906. 



Harper, R. A. 



Cell Division in Sporianga and Asci. Ann. Bot. 13 : 4(11 . 1S99. 



Sexual Reproduction and Organization of the Nucleus in Mildews. 

 Carnegie Inst. Pub. 37. 1905. 



Ikeno. S. 



Blepharophlasts in Plants. Biolog. Centrabl. 24 : I'll. 190-4. 



Kusano, S. 



On the Nucleus of Svnchvtrium Puerariae. Bot. Mag. Tokyo. 21 : 118. 

 1907. 



Lawson, A. A. 



On the Relation of the Nuclear Membrane to the Protoplast. Bot. 

 Gaz. 35 : 305. 1903. 



Lilhe, F. R. 



Elementarv Phenomena of Development of Chaetopterus. Jour. 

 Exp. Zool."3 ; 153. 190(3. 



Mead, A. D. 



Origin and Behavior of Centrosomes in the Annelid Egg. Jour. Morph. 

 14 : 2. 1898. 



Olive, E. W. 



Cell and Nuclear Division in Basidiobolus. Ann. Mycol. 5 : 404. 1907. 



Rvtz, W. 



Beitr. Kennt. Gat. Synchytrium. Centrabl. Bakt. 18 : 635, 799. 1907. 



Stevens, F. L. 



The Compound Oosphere of Albugo bliti. Bot. Gaz. 29 : 149, 225. 1899. 



Some Remarkable Nuclear Structures in Svnchvtrium. Ann. ;\Ivcol. 

 5 : 480. 1907. 



Stevens, F. L. and A. C. 



Mitosis in the Primarv Nucleus of Svnchvtrium Decipiens. Bot. 

 Gaz. 35 : 405. 1903.' 



Wilson, E. B 



The Cell. A'lacmiUan Co. 1904. 



Explanation op Plates XIX and XX. 



The figures were made with a Spencer 1.5 mm. achromatic, oil immer- 

 sion objective and a Zeis compensating oci-'lar 12 giving at the table a 

 measured magnification of approximmately 4000 diameters. They were 



reduced to 2-3 of their original size exactly canceling the enlargeinent due 

 to the camera and rendering the figures the same size as they were seen in 

 the field of the microscope, namely enlarged 2670 times. All are camera 

 drawings. 



Fig. 1. Early anaphase; a blob of chromatin at one pole, at the other 

 4 chromosomes, one covering another. 



Fig. 2. Telophase considerably later than fig. 1. Showing the pro- 

 cess of transformation of the chromosomes and also the beginning of the 

 nuclear vacuole which is without a menibrane. 



Fig. 3. Nucleus in wich the rays are beginning to be associated with 

 the edges of the nuclear vacuole. 



Fig. 4. Nucleus with two asters the rays of each of which are begin- 

 ning to form the nuclear membrane. 



