1918] DUFRENOY—PINE NEEDLES 453 
In like manner all the different organs must have descended 
from the ancestral organ; each lost the possibilities corresponding 
to the function it lost, but retained and perfected those which made 
it more adequately adapted to its special function. The following 
table shows how the different organs of pines may be derived from 
one another, according to data given by studies of abnormal, 
intermediate forms at the Biological Station of Arcachon. 
fertile (reproduction) ; nee a 
Primitive organ { green (assimilation) > juvenile leaf erie dle 
storage of reserves > cotyledonary needle (7) 
self-protecting > scale 
A needle which has specialized in the assimilation of carbon 
is itself a sort of assimilating organ; leaves of angiosperms are 
another. 
Needles are the physiological leaves of pines. They differ 
from leaves in that they are perennial and are much less fragile. 
Typical leaves are temporary, delicate, perfectly shaped for intense 
assimilation, but unable to stand bad weather. Pine needles last 
several seasons. They have efficient xerophytic adaptation and 
can stand the roughest weather on arid lands, windy mountain tops, 
or storm beaten coasts (15, 16, 17). 
In conclusion, thanks are extended to Professor FRon for his 
valuable encouragement, and to Dr. F. Latesque, Honorary 
President of the Station Biologique d’Arcachon, for his ‘many 
kindnesses and valuable documents.’ 
STATION BIOLOGIQUE D’ARCACHON 
LITERATURE CITED 
1. Boopte, L. A., Solitary and concrescent leaves of Pinus. 
14:19-26. 1915. 
2. BouyGuEs, a, Contribution 4 l’étude du systéme libero-ligneux des 
Ceyptoghnits siancilaires. Act. Soc. Linn. Bordeaux 9: 1905. 
° We are also indebted to The Bureau of Plant Industry, Professor R. T. Baker, 
Dr. Fracoso, and Professors onp and Marre for most valuable papers; 
while part of the expenses involved in these researches was defrayed by a grant from 
the Association Francaise pour l’Avancement des Sciences. 
New Phytol. 
