382 BOTANICAL GAZETTE [MAY 
more needles than any pine of today does normally, but in this 
feature and in the fact that they have considerable axis supporting 
them they remind one of such fascicles as those of P. excelsa (fig. 3), 
which were produced after bud injury. The fascicles of the fossil 
form, too, are described as terminal as well as lateral, and must 
have grown out into branches and the main axis, just as has some- 
times been observed in the living pines. The lack of differentiation, 
too, between the primordial and fascicled leaves and the persistence 
of the former on old branches 
afford a full explanation of the 
transitions “which have been 
found between these leaves in 
the living pines and also of the 
occasional “‘revival’’ of pri- 
mordial leaves on old trees. 
In fact, no better “general- 
ized type” could be desired 
for the ancestors of the pines 
than FonTarnE has described. 
Two other fossil forms have 
also significant features. In 
Prepinus of the Cretaceous, 
whose discovery we owe to 
JerFFrey (14), the spur shoot 
has 20 or more leaves. These 
leaves are not cyclic, but are 
spirally arranged, and are stated to be subject to considerable varia- 
tion in number. This spur shoot is nothing more nor less than a 
small branch with closely set leaves, very similar to the condition 
described in the seedling of certain pines and in the adult after 
injury. This spur is apparently deciduous, however, but JEFFREY 
(15) has described one from the Triassic (Woodworthia) with 
very persistent spur shoot, remaining 50 years or more attached3 
} 
; 
2 
a 
Fic. 2.—Leptostrobus longifolius: fro: 
FONTAINE (9, pl. 102); reduced one-half, 
3It is recognized that Jerrrey considered this form a pine specializing oe se 
direction of the araucarians and not as an ancestor of the pines and their allies. 
Since, however, it has been recently shown that no authentic abietinean forms nave 
been described in the strata prior to it (see GorHAN 10 and THOMSON AND ALLIN 28), 
this form must stand as the ancestor of the pines and their allies until some - 
fascicle-leaved conifer displaces it. 
