594 JUST 



of Nathorst, Thomas, and Bancroft was climaxed by that of Harris and Florin. 

 The latter has applied this technique to all groups of gymnosperms and clari- 

 fied numerous problems of classification. 



The success story of the application of this technique is the reconstruction 

 by Florin of the oldest known fossil cycad (Triassic), Bjuvia simplex, from 

 two frequently associated organs, a leaf (Taeniapteris) and a megasporophyll 

 (Palaeocycas). Beyond that, the elaborate studies of the cuticular characters 

 of gymnosperms have disclosed that this group is no longer tenable for rea- 

 sons other than convenience, but that it includes widely separate taxa. This 

 is especially true of the cycads and the "fossil cycads" (cycadeoids). The 

 resemblances between these two groups are largely external and not indicative 

 of close relationship. Using cuticular characters, much doubtful cycadophyte 

 material could be definitely assigned either to one or the other group. Thus 

 the true cycads, long considered relatively unimportant in the fossil record, 

 have been re-instated as an important group of fossils, even though they can 

 no longer be regarded as "fossil cycads." On the other hand, wholly new 

 and striking types of cycadeoids have been described from other localities, 

 notably from Austria by Krausel, that resemble small sunflower heads more 

 than they do other cycadeoids. 



Another famous case of reconstruction is that of the pteridosperm Calym- 

 matoiheca hoeninghausi {Lyginopteris oldhamia) by Jongmans (1930), who 

 found various organs in organic connection. Such cases are rare, indeed, but 

 prove that the possibility always exists. The achievement as such is greater 

 than the temporary inconvenience of trying to work out which of the organ 

 genera should be redefined to include the others and then be applied to the 

 whole plant. 



Although Zimmermann's Phylogenie der Pjlanzen (1930) was never written 

 as a textbook of paleobotany, it has had a far-reaching effect on paleobotani- 

 cal as well as neobotanical research. His telome theory, as proposed in this 

 work, has been widely applied in the interpretation of complex structures, 

 especially that of conifer cones by Florin and that of the angiosperm stamen 

 by Wilson. Since then Zimmermann has formulated several basic morphologi- 

 cal principles traceable throughout the evolution of the plant kingdom. Lam 

 followed Zimmermann and Sahni in applying certain morphological concepts, 

 notably stachyospory and phyllospory, to the classification of vascular plants 

 and proposed various categories which are roughly indicative of the time 

 sequence as well as increasing morphological complexity, namely, Palacostclo- 

 cormophyta, Mesostelocormophyta, and Neostdocormophyta (gymnosperms 

 in part and angiosperms). Similarly, new classifications of lower plants have 

 been proposed. The last of several proposals of this kind, advocating the 

 adoption of more than two kingdoms, came from a paleontologist, Raymond 

 C. Moore, who wishes to re-instate Haeckel's Protista (1866), in an effort to 

 broaden the contents of the proposed Treatise on Invertebrate Paleontology 



