759 



Nachdruck verboten. 



Non-sexual Conjugation of the Nuclei of the adjacent Cells 



of an Epithelium. 



Von Prof. Johk A. Rxdeb and Mary E. Pennington. 

 With 5 Figures. 



The occurrence of amoeboid nuclei has been frequently observed; 

 amongst the earlier authors who have noticed them Eimer may be 

 mentioned. The steps preparatory to the disintegration of the macro- 

 nucleus of Ciliata, according to Maupas and Hertwig, are accompanied 

 by amoeboid changes. Gruber has also observed such phenomena in 

 Ciliata. 



In the intestine of the land-Isopods observed by us the epithelial 

 cells are very large with correspondingly large nuclei. These often 

 exhibit the most marked amoeboid changes of configuration in place, 

 within the cell body of which they form a part, as shown in Fig. 1 

 in which the nuclei of two adjacent cells are shown with processes 

 reminding one of the pseudopodia of an Amoeba. The nucleoli are 

 also shown to be amoeboid, and at least one, though often more than 

 one, nucleolus has been observed in each nucleus. It is also seen 

 that these nuclei approximate one wall of the cell more closely than 

 another with their pseudopodial extensions. The nuclei of adjacent 

 cells seem in fact to be moving toward one another. This figure is 

 from a preparation of the intestinal wall of Porcellio, stained 

 with methylene-blue , as viewed under a 1 / 12 inch homogeneous 

 immersion-lens. 



In Fig. 2, the further steps of the conjugation of the nuclei of 

 adjacent cells of the intestinal epithelium of Porcellio are shown. 

 In the lower pair of cells the pseudopodial extensions of the two 

 nuclei have just reached the line of separation between the two cells 

 and are not yet quite in contact. In the upper pair of cells of Fig. 2, 

 diagonally opposite each other, the two nuclei have extended themselves 

 into the adjacent or tangent corners, where they have completely fused 

 with one another. 



In Fig. 3, a pair of cells below have their nuclei fused into a 

 single curved sausage-shaped body extending from the body of one 

 cell into that of the other, so that here complete nuclear conjugation 

 has again occurred. This, however, is supplemented by the nucleus 



