COPRINUS STERQUILINUS 



157 



Figs. 87 and 88. In Fig. 87, in the centre of the drop, is a single 

 spore which has germinated and has given rise to a mycehum the 

 branches of which tend to grow outwards in a radial direction. 

 The mycelium was at first completely haploid, i.e. its nuclei were 

 separated and non-conju- 

 gate (c/. Fig. 52, p. 83 ), 

 and in this condition its 



cross-walls were all simple \ V v \ cil 



and not provided with 

 clamp-connexions (c/. Fig. 

 51, F, p. 81 ) ; but now, 

 the mycelium is turning 

 from the haploid to the 

 diploid condition, i.e. the 

 nuclei are becoming paired 

 and are beginning to divide 

 conjugately. This change 

 is always accompanied 

 by the development of 

 clamp-connexions at the 

 cross-walls, and these out- 

 ward and visible signs 

 of diploidy have already 

 made their appearance at 

 ddd in the radial hyphae 

 cc. Soon all the main 

 radial hyphae will come to 

 resemble cc, and then the 

 whole mvcelium will have 



Fir:. 87. — Coprhnis .stcrrjii{l!)ni.s, a liomothallic 

 Hymenomycete. Diagram of a young my- 

 celium, to show the beginning of tlie pro- 

 (hiction of clamp-connexions and of liyplial 

 anastomoses : a, a basidiospore wliifli has 

 germinated ; b b, leading hypliae growing 

 radially away from the centre of the my- 

 celium. On some of the leading hyphae c c 

 clamp-connexions d d hav^ now appeared, 

 thus indicating tliat the mycelium is passing 

 from the haploid to the diploid phase. 

 Lateral hyphae e e, growing irregularly and 

 more or less tangent ially, are beginning to 

 establish anastomoses in the older part of the 

 mycelium, as at //. Highly magnified. 



changed from the haploid 



to the diploid state. An older mycelium which, as indicated by 

 the development of clamp-connexions at all the cross- walls, is 

 completely diploid is shown in Fig. 88. 



Let us again turn to the mycelium illustrated in Fig. 87. At 

 first all its hyphae had free ends ; but already, as may be seen at 

 ///, the end of a lateral hypha has grown toward and has fused with 

 a radial hypha, so that the mycelium as a whole is becoming netted. 



