The early History of the cellular elements of the Ovary 

 of a Phryganid, Platyphylax designatus Walk. 



Wm. S. Marshall 



University of Wisconsin, Madison. Wisc. IJ.S.A. 



(From the Zoological Laboratory, University of Berlin.) 

 With Plate XV and XVI. 



The larva of Platyphijlax designatus can be obtained throughout 

 the year in some Springs in the vicinity of Madisox, Marshall and 

 VoRHiES (26); the pupae are very easy to get, and the imagoes may 

 readily be caught if one visits the Springs during the few days they 

 are alive. My material was all obtained at this place and the work 

 on the following paper done in the Zoological Laboratory of the 

 University of Berlin. I desire to thank Prof. F. E. Schulze for the 

 use of the laboratory and library of the Zoological Institute. 



The principal preserving fluid used was Flemming's, both weak 

 and strong; a modification of Gilson's and Hermann's Solution were 

 also used. Flemming s triple stain and Heidenhain's iron-haema- 

 toxylin I made use of more than any other stains, but sections were 

 stained with a number of the commoner fluidS; and with safranin 

 alone; this last, when well washed out, gave very beautiful results. 



The question concerning the origin of the cellular elements of 

 the ovary has been discussed by many who have worked with the 

 ovaries of different insects; such good reviews can be found in the 

 works of Korscheit (22), Gross (11) or Henneguy (17) that it seems 

 superfluous to repeat the subject here. The discovery of nuclei and 

 cells within the ovarian tubule occurred long ago; then came the 

 question as to the origin of the different cellular elements, a question 

 on which nearly every one who has worked on the subject has had 

 something to say. Workers like Huxley (20), Lubbock (25) and 



