STUDY. OF THE GENICU1 Â OF COB M.I.IN.l'. 17 



dangerous to give further details on this point, as the material worked 

 over has been from a dried specimen. If might be stated, however, 



thai at least a small portion at tin- base of the filamentous <vlls is not 

 calcified and flexible as in the genicular portions of the other 

 ( 'orallinas. 



These peculiarities of structure suggest the convenience of omitting: 

 the above mentioned species from the general discussions of genicula. 

 The following chapters will be applicable to the other members of the 



mllince, except Amp. aspergillum unless it is specially mentioned. 



STRUCTURE OF GENICULAR CELLS AND COMPARISON 

 WITH ARTICULAR CELLS. 



The genicula of Amp. dilatata, Amp. echigoensis, Amp. Bowerbankii, 

 Amp. cplicnra, etc., — probably all members of the section Eurytion, 

 Dene. — are built up with several zones of periclinal cells. The genicula 

 of this category have special characters and should be treated further. 



In Amp. rigida the genicula seemed to have been built up with 

 two zones of periclinal cells. They are, however, always formed of a 

 single zone, the cells being often intertwined at the equatorial points 

 and looking like two zones, cf. Cor. verte. Jap. PI. I. fig. 6. 



The presence of the extragenicular portion is an important 

 matter. Former investigators seem to have overlooked this. Xelsox 

 and Duncan 1} remark that the long cells (of articulus) are often 

 distinctly continuous with the filiform cellular processes of the 

 articulations (genicula), especially with the deeply seated ones. They 

 seem to have noticed nothing about the extragenicular portion. 

 Among the multitudinous illustrations of "Tabulae Phvcologicie " 2; 

 only two figures indicate this circumstance in any degree. And in 



1) ]. c. p. 20C 



2) Vol. VIII Taf. 5fi. and 60. 



