Nucleoli During the Oogenesis of the Dragon-fly. 227 



Explanation of Plates. 



All the figures were drawn either from caraera-lucida outlines, or, 

 when the cells were too large for that, from simple projection. In all 

 the drawings, except Fig. 40 which was made with a 1/12 inch oil- 

 immersion lens, a 1/16 inch oil-immersion lens with 1 inch eyepiece was 

 employed, giving a magnification of about 1450 diameters. In reproducing, 

 the figures have been reduced one-fourth, so that the actual magnification 

 is about 1087 diameters. 



Plate 13. 



{Plathemis Jydia.) 



î'ig'- 1) 7, 12, 14 and 19 are from cells stained with iron-haema- 

 toxylin. 



Fig. 2 — 6, 8 — 11 and 13 are from cells stained with Flemming's 

 triple stain. 



Fig. 15 — 18 are from cells stained by the borax-carmine, methyl- 

 green method of Obst. 



Fig. 1. Longitudinal section of the anterior end of the egg-string 

 through end-filament and germinal area. Showing : a peritoneum ; h fol- 

 licle-cell : (■ end-filament cell; d elongated filament-cell; e germ-cell. 

 A, in this figure marks the end-filament, B the germinal area with cells 

 in syncytium and C the growth area. 



Fig. 2. Cross-section of the germinal area : a wrapping of chromatic 

 spireme around oxyphile nucleolus. 



Fig. 3 — 8. Successive stages in the condensation of the chromatin 

 skem around the nucleolus. Fig. 7 shows beginning of yolk-nucleus. 

 Zool. Jahrb. XXTII. Abt. f. Anat. 15 



