208 



RESEARCHES ON FUNGI 



B 



Fig. 89. — Coprinus sterquilinus. Nuclei 

 in living basidia. A, cross-section 

 through a living hymenium shewing 

 a single nucleus with a nucleolus in 

 all the basidia ; I, long basidium ; 



are only represented by their 

 bodies and contain no more than 

 a single nucleus (the fusion- 

 nucleus), while the paraphyses 

 are still extremely slender. At 

 10 P.M., a section taken at the 

 same level from another block 

 of material exhibited the appear- 

 ance represented in Fig. 90, A, 

 During the preceding five hours, 

 sterigmata had developed upon 

 the ends of the long basidia. 

 Moreover, nuclear division had 

 taken place. The stages in the 

 division of the nucleus were 

 studied in sections taken be- 

 tween 5 P.M. and 10 p.m. ; and 

 some of them are illustrated in 

 Fig. 89, B. Up to 6 p.m. the long 

 basidia each had but one nucleus 

 {a and 6) and were therefore 

 similar to the long basidia shown 

 in Fig. 89, A. By 8.30 p.m.. 



s, short basidium ; p, paraphyses ; 



g glycogen particles (staining brown howeVCr, SOme of them already 



with iodine) in all the long basidia. 



B, basidia showing nuclear changes ; 

 a and b, with one nucleus each ; c 

 and d, with two nuclei each ; e, f, 

 and g, with four nuclei each ; g 

 shows the beginning of sterigmata ; 

 h, a basidium with four spores — the 

 nuclei have crept up into the spores 



possessed four nuclei (e,/, and g), 

 the intermediate binucleate con- 

 dition (similar to that shown for 

 two short basidia at c and d) 

 having been passed through in 



into which also the cytoplasm is 



passing, so that the body of the the preceding two and a half 



basidium contains a large vacuole ; , ^, t • • r i i 



hours. Ihus the division oi the 



t, an isolated spore containing one 

 nucleus ; j and k, two spores each 

 containing two nuclei ; I, spore with 

 four more or less definite clear spaces 

 in the centre which are possibly 

 nuclei. Magnification, 352. 



original fusion-nucleus first into 

 two smaller nuclei and then into 

 four still smaller nuclei was 

 accomplished in less than three 

 hours. Possibly in a single basidium the two successive biparti- 

 tions of the original nucleus take place in about an hour and a^ 



