J20 MARGARET C. MANX. 



Stage II. In the upper middle portion of the oviduct the 

 spindle is beginning to break down and the chromosomes are 

 becoming scattered. In most of the unfertilized eggs studied the 

 second maturation spindle remains parallel to the surface of the 

 egg and there breaks down, the fibers splitting off and carrying 

 the dumb-bell shaped chromosomes with them. This process 

 varies in completeness in different ova. The spindle may be 

 evident after most of the chromosomes are vesiculate, or it may 

 disappear almost completely as the chromosomes scatter. 



Eggs were found in the upper middle portion of the oviduct in 

 ten cases, and in all forty eggs had broken spindles and scattering 

 chromosomes. Thirty-one of these were in the upper half of the 

 oviduct. The breaking down of the spindle results, at times, in 

 a simulation of multipolar spindles but their irregularity and the 

 fact that the chromosomes are usually widely scattered indicate 

 that they result from the breaking down of a single spindle. 

 Sometimes the spindle, when quite degenerate, is no longer 

 fibrillar but appears as a dense homogeneous mass of material of 

 a very distorted shape. 



In two oviducts eggs were found in which the spindle was 

 central, and the cytoplasm about it unusually dense. The 

 spindle appeared shrunken and the chromosomes had coalesced 

 into a compact mass. Such eggs were also found well down in 

 the oviduct. 



Stage III. The vesicle formation which began in Stage II. 

 proceeds until multinucleate cells are formed. A liquid gathers 

 about a single chromosome or a group of them. The chromo- 

 somes then swell and break up into large and finally into small 

 granules so that the nuclei assume the typical resting condition. 

 They vary greatly in size and number, different cells in the same 

 oviduct containing from one to ten nuclei which differ greatly in 

 size. The appearance of the nuclei differs with the fixative used. 

 In eggs fixed in Benda the chromatin lines the inside of a clear 

 vesicle, most of it being in a mass on one side. In eggs fixed in 

 Zenker the chromatin appears as granules on a net. Central 

 spindles in different stages of degeneration were found in three 

 oviducts. In one of these one egg contained a central spiiidK- 

 while the other three resembled typical resting cells. In the 



