PINES (PINACEAE) 451 
maining portion of the nucellus hardens, so that the seed when 
nature resembles some of the stone fruits, such as the Plum, 
although it is a seed and not a fruit. 
It is obvious that a seed is simply a transformed megaspo- 
rangium. In the Cycads a seed is a megasporangium which has 
its outer portions modified for protection and contains within 
a female gametophyte bearing a 
young sporophyte. Thus the re- 
duction of the female gametophyte 
through the Pteridophytes and 
finally its retention in the mega- 
sporangium in the Cycads so that 
the young sporophyte also develops 
within the megasporangium were 
important steps in the evolution of 
the seed. 
“Although the Cycads resemble 
Ferns in having swimming sperms, 
and in having leaves and stems that 
are Fern-like, they contrast with 
them in such new features as differ- 
entiation of strobili, simpler ga- 
metophytes, pollination, growth of 
pollen tubes, and the seed. 
Pines (Pinaceae) 
The Pines are a subdivision of the 
Pine family (Pinaceae). In addition 
to the Pines, the Pine family in- 
cludes the Spruces, Firs, Hemlocks, ° — anaes 
Larches, Cedars, Redwood,Cypress, _ F16- 400. — Pine sporophytes. 
and others. The Pine family is an ee 
exceedingly important one because it includes a large proportion 
of the trees from which lumber is obtained. The Pine family 
belongs to the order of Conifers (Coniferales), so named because 
of the cones which they bear. Not all of them, however, bear 
dry cones like the Pines, for some have fleshy fruit-like structures, 
as the berry-like structures of the Junipers illustrate. All of the 
representatives of the Pine family are interesting, but a study of 
their life history will be limited to that of the Pine. 
oe 23 ee ~ I 
