74 



MORPHOLOGY OF SPERMATOPIIYTES 



regarded the oviiliferous scale in Abieteae as an open carpel, 

 whicli is lacking in Cnpresseac. 



One of the simplest explanations of these problematical 

 structures Avas that proposed by Sachs ^^ in 1868, and afterward 

 elaborated more fully by Eichler.^® They contended that the 



Fio. 59. — Almoriiial struliili of Ahiis sp. : tliu staminate cone at l.iwer right-hand oornor 

 is almost nonual ; all the utherb have inierosporaHgia both above and below, witii 

 ovulit'erous seales between. 



bract is a carpel ;ind the ovulifcrous scale a ligTilar (:>utgro\vth 

 from it, calling attention to a similar condition of things in the 

 leaves of Isoctes and Sclar/ineUa. Such a ligular placenta does 

 not appear in certain groups, as Cupresseae,Taxodieae, and Podo- 

 carpeae, and in these cases the bract is evidently an open carpel. 

 The simplicity of this explanation has commended it td writers 

 of text-Ill loks, and hence it is ])t'i'haps the view whicli is most 

 current. 



Tn 1S(.!0 Van 'I'iegheni ^"^ presented his contdusidus based 

 upon anat(imic;il structure — a new ])oiut of view. lie claimed 

 that the ovuliferous scale is the first and only leaf of an axillary 

 branch, although he suggested the possibility of Uvo fused leaves, 

 ;nid liases his sttitement on the course and oricutation of the 

 bundles. He states that the bundles of bract and ovulifcriuis 

 scale leave the main axis each in its own sheath, aiul thus repre- 

 sent iiide]ieiident systtmis of luiudles; that the up])criiiost 

 divides and forms an ;irc with iu\-erleil orieulation, the arranoc- 



