428 TRANSACTIONS AND PROCEEDINGS OF [Skss. lvi. 



Fig. 47. The ground substance of the nucleolus exhibits a radial 

 striation ; peripheral, j>. e., and a central, c. e., endo- 

 nucleoli, &c. 



Fig. 48 is a diagrammatic representation of the achromatic ele- 

 ments of a normal cell. We find a cell membrane, 1 ; o. 

 cell zone, 2; a nuclear membrane, 3; a nuclear zone, 4; a 

 nucleolar membrane, 5; a nucleolar zone, 6. 



The dark lines indicate the endonucleolar network, 

 consisting of the central endonucleolus — (a) ; the proximal 

 or coronal set of small endonucleoli (h) ; the distal set of 

 endonucleoli {d) ; in communication with " a " antl " ^/' 

 by the fibril" c ; e, the pores in the nucleolar membrane ; 

 f, the nuclear framework giving ofif branches to the 

 achromatic framework of the nuclear chromosomes, ehr.; 

 (j, the pores in the nuclear membrane ; //, endonucleolar 

 fibrils permeating the cell substance and intercommuni- 

 cating at i ; Ji, the endonucleolar fibrils establishing the 

 continuity of the plasm between neighbouring cells. 



The dotted lines are meant to indicate the paranuclear 

 achromatic substance in the centrosome, /; in the archo- 

 plasm, m, in the cell zone, n; in the nuclear zone, o, and in 

 the nucleolar zone, p. 



Fig. 49*"'^ Cells as occasionally met with in the antipodal region 

 of embryo-sac in Scilla 7iiifa7w, suggesting that the true 

 antipodal cells may undergo conjugation analogously to 

 the two primordial cells forming the primary endosperm 

 cell — m.p.c, micropylar cell; ^ a.iJ.c, two antipodal 

 cells ; p. 11., paranucleolar body. 



Fig. 50^*"^. The meclianism of conjugation. The endonucleolar 

 fibrils pulling the nuclei, n, the nucleoli, nl., and ulti- 

 mately the endonucleoli, end., together, and then 

 rearranging themselves round the newly-formed endo- 

 nucleolus, ij, end. 



