1890.] Origin of the Plane-Trees. 799 
return a reprint of his paper, together with other works of his. 
In his letter of acknowledgment he expresses a deep interest in 
the subject of basilar lobes, but does not say whether he accepts 
my interpretation of their significance. P. basılobata, as I have 
pointed out, is so closely related in other respects to P. nobilis, 
that but for this feature I should have included it in that species ; 
and Sir William Dawson, who had already figured it from the 
Canadian Laramie as P. noġilis, has, in his Geological History of 
Plants, proposed to call it P. noddıs var. basllobata. Prof. Jankó 
would therefore naturally have affixed to this species, as to P. 
nobilis, his sweeping verdict, “ non est Platanus.” 
But the question, as it seems to me, is not so much whether 
these aberrant forms really belong to the present genus Platanus, 
as strictly limited by the characters presented by the few surviving 
species of that ancient type, as whether they represent the ances- 
tors of these modern forms. The genus Platanus, like its close 
relative Liquidambar, like the monotypic Liriodendron, and like 
those holding-over forms of coniferous trees, the Sequoia and the 
Ginkgo, presents all the indications of being the last of a long 
lineage, and paleobotany, in this as in the other cases named, 
shows that it was once far more abundant than at present. So 
prominent a group must have had an ancestry, and the archaic 
forms found in the American Cretaceous deposits bear evidence 
of constituting that ancestry. 
One of the distinctive links in this chain of evidence proves to 
. be the presence of basallobes. Nearly effaced in the latest living 
type, P. orientalis, this feature, nevertheless, sometimes occurs 
there, and was actually found by the searching observation of 
Professor Jankó, who, without the slightest suspicion of its sig- 
nificance, but true to his instincts of describing everything he 
found, described it in the following language: “ Den Blattgrund 
betreffend, fand ich bei P. orientalis einen sehr interessanten Fall, 
dessen ganze Entwickelung ich beobachten konnte und welcher 
als Uebergangsform von der lappigen in die schildförmige betrach- 
tet werden kann. Bei jenen Blättern nämlich, wo der Ausgangs- 
punkt der drei oder fünf Hauptnerven nicht an der Grenze von 
Stiel und Spreite ist, vergrössert sich nicht selten der letzte Zahn, 
