Schaxel, Bedeutung des Chromatins in Metazoenzellen. ?gg 



Fig. 31. Ovarian egg of the pigeon, showing archoplasm and centrosome 

 at one pole. 



Fig. 32. Striated muscle fiber from eye muscle of horned toad, showing 

 transverse bands and the regulär arrangement of microsomes as in an aster. 



Plate Ic. 



Fig. 5. Ovarian egg of Limzihts, showing crescent shaped nucleolus con- f~ 



taing karyolymph, the germinal vesicle contracted showing coagulated karyo- 

 lymph partly surrounding the germinal vesicle and probably extruded from the 

 germinal vesicle. 



Fig. 6. Ovarian egg of the tortoise showing a body close to the germinal 

 vesicle resembling a sphere with a centrosome. 



Fig. 7. Ovarian egg of the tortoise, showing a large spherical mass in cyto- 

 plasm, near the center of which there is a spherical clear area suggesting a cen- 

 trosome and sphere. In the cytoplasm many irregulär masses of metaplasm. 



Fig. 8, 9, 10, 11, 12. Ovarian eggs of the tortoise showing arrangement of 

 amorphous metaplasm, yolk nucleus- and sphere, showing that the sphere is not 

 identical with metaplasm. 



Fig. 13. Spermatocyte of Papilio rutuhis, showing centrosome in aster. 

 It resembles the true centrosome and aster of Ascaris, and suggests that it is a 

 persistent feature of the cytoplasm like the similar body in the eggs of Clemmys. 



Fig. 14. Sperm cell of Papilio showing the centrosome and at opposite pole 

 of nucleus the Nebenkern derived from remuants of the spindle in the last karyo- 

 kinesis. The Nebenkern and the Centrosome being different structures. 



Fig. 34. Diagram showing transverse section of ovarian tube of Limtdus. 

 m point of attachment of tube to rest of ovary. Opposite* this o the oldest egg 

 x- and n next oldest etc. the youngest being at a, then b, c, d, e, f. The vitelline 

 body is taken from actual preparation of corresponding size and having the same 

 eolation to the germinal vesicle and to the point of attachment of the egg. The 

 egg axis drawn through the body and the nucleus shows no constant relation to 

 other parts. Compare i and j, o and 1. 



Herr Dr. J. Schaxel (Jena) hält seinen angezeigten Vortrag: 



Die Bedeutung des Chromatins nach Untersuchungen 

 an Metazoenzellen. 



Von Julius Schaxel (Jena) 



(Mit 5 Figuren im Text.) 



Seit wir Kenntnis von der mitotischen Kernteilung haben, 

 hat die chromatische Substanz des Zellkerns durch ihre eigentüm- 

 liche Erscheinungsweise in individualisierten Gebilden beim Tei- 

 lungsvorgang, den Chromosomen, die besondere Aufmerksamkeit 



