No. 454-] OPHIOGLOSSACEyE AND MARSfLIACI-.K. 763 



between the Ophioglossaceae and the true ferns, and thinks tlicy 

 are probably more nearly related — although very ivmoulv to 

 the lycopods. In his most recent work {loc. cit. Xo. \'. p. J5 

 however, he recognizes the importance of the dccidolly In n liki,' 

 character of the gametophyte and -recedes somrwli it tiom ili.- 

 extreme views expressed in the earlier paprr. llr sc' in^ >ti!l 

 unwilling, however, to give up the honiolo-A hiiwrni thr 

 phyll in Ophioglossum and Lycopodium. It is hnd tli.it all tlu- 

 pteridophytes are reducible to a common strobiloid t\i)r, whidi 

 is most clearly seen in the lycopods and luiuisetat c;r. l)ul wliit h 

 is believed to be recognizable in the ferns as well. W 1U1 tins 

 view the writer has been unable to agree. 



Bower thinks it inconceivable that a large-leaved type could 

 originate directly from any conceivable form of bryophyte sporo- 

 gonium, and therefore concludes that all the primitive j^tendo- 

 phytcs must have been microphyllous. To the writer there 

 seems to be no greater difficulty in assuming that a single leaf- 

 like organ may have been developed at the base of the sporogo- 

 nium {Mosses and Ferns, p. 5iS)than that a scries of small 

 leaves should be developed as eruptions from its Mirtacc. W 11} 

 both forms may not have been developed quite in.lcp.'iuk iUlv ir> 

 not clear, either from the evidence of comiwrativc mnrphok.g). 

 or from the fossil record. That a special assimilative .structure, 

 remotely comparable to a leaf, may originate Irom the base <>t 

 the sporogonium is shown in many mosses, wheie the apopi}^!-^ 

 is of this nature. In certain species ot Splaehmmi the ap..p 1} ^is 



which might almost be compared to a pertnhale leat. ( M ("Ui^( 

 there is no question of a direct homoloi;) between tne api-p i\s!- 

 of a moss and the leaf of a vascular plant, but the taei patent 

 that the sporogonium of a moss may give use to a >pe( la assim- 

 ilating organ, and it is therefore quite coneei\able that t u pi" 

 genitor of the large-leaved fern> may ha\e ariMU t!<mi smhu 

 bryophytic type by an analogous tormation ot a * m "'--'"^ 

 which became a true leaf subtending a sporogenou^ ^ti i,( am. 

 much as is actually seen in Ophioglossum. 



That the Ojjhioglo.ssacene represent an ascending series, as 

 Professor Bower (Bower, loc. cit. No. 5» P- -33) l>^'li^-\"^'^- 



