INTRODUCTION TO CEYPTOGAMIO BOTANY. 



193 



placenta of Eucheuma is free, except at the very base, and 

 is suspended in the middle of the nucleus by delicate filaments 

 proceeding from it to the walls of the nucleus, while in Solieria 

 (Fig. 44, e) it is perfectly free, with the exception of similar 

 connecting threads. It is a curious matter that there should 



Fig. 47. 



a. Nucleus of Eucheuma isiforme, J. Ag., showing the placenta at- 

 tached to the wall of the nucleus by delicate threads, and supported at 

 the base, magnified. 



h, Moniliform threads, bearing spores at their apex. Both after 

 Harvey. 



c. Transverse section of part of a conceptacle of Gelidium corneum, 

 magnified, showing the dissepiment, with the spores growing from its 

 two faces, and the connecting filaments, from a specimen communicated 

 by Mrs. GriflSths. 



d. Spores more highly magnified. 



be another genus, Mhabdonia (Fig. 45, a), which differs only in 

 each cell of the moniliform threads, producing numerous spores 

 by the division of its endochrome, and, consequently, comes 

 under a distinct section, at least in an artificial arrangement ; 

 for it is quite clear that the multiplication of the spores arises 

 merely from a vital energy carried a step farther than in 

 Solieria. Reduce the threads to a single joint, and there is 

 no essential diflference. 

 11. Sph^kococcoide^, J. Ag. 

 13 



