Heredity and its Bearings on Atavism. 127 
Fig. 1. 
Fig. 1.—An ideal cell showing: the general cell-plasm (1), the finer structure 
of which is not seen; two archo-plasms and centrosomes (2); a vacuole (3); an 
excretory tube (4); an endonucleolus (5a), with its radiating channels (5d); a 
nucleolus (6); chromatin segments (7); the pale perinucleolar nucleoplasm (8); 
the denser peripheral nucleoplasm (9); a space (10) inside the nuclear mem- 
brane (11); a chlorophyll band (12a), with pyrenoids or starch centres (12d), 
and a tube conveying food from them to the nucleus (12c). 
Fig. 2a.—Two nuclei about to conjugate in the Embryo-sac of Scilla nutans. 
The nuclear membrane n.m., with broad, p.a., and narrow, p.8., pores; 
peripheral chromatin segments, chr!, and central ones, ch7*; nuclear hyalo- 
plasm, 2.2., with tubular fibrils, x.f., and solid strands, n.f*. 
The nucleolus exhibits a nucleolar membrane, 1; a peripheral set of 
endonucleoli, 2; a ground substance, 3; irregularly distributed central 
endonucleoli, 4; with radiating fibrils, 5. 
Fig. 2b.—A nucleolus of the primary endosperm. cell in yosurus minimus, 
showing: a nucleolar membrane, 7.1.7. ; radiating fibrils, 7.7., in a peripheral 
paler zone of the nucleolus; four comparatively large peripheral endonucleoli,2 ; 
a set of proximal or coronal endonucleoli, end; and a fold, fold, around the 
central endonucleolus, d. 
(Reduced from G. Mann’s paper on the ‘‘ Embryo-sac of Myosurus.”’) 
