282 PHYLUM XIII. STROBILOPHYTA 
mon ‘‘ White Pines’’ have five leaves in a fascicle, the 
“Yellow Pines” three or two. An Arizona pine has but 
one leaf on each twiglet. : 
509. In the Cypresses (Family Cupressaceae), and 
Thuyas (Family Thuyopsidaceae) the woody cones are 
small and composed of only a few scales, and the leaves 
are small and scale-like. In the Junipers (Family Juni- 
peraceae) some twigs bear scale-leaves and others flat 
leaves, while the cone scales are few and fleshy, so that 
the cones are fleshy. In the Yews (Order Taxauzs) the 
reduction in the cones is carried so far that but one scale 
remains, and that has become fleshy. In the proper 
Yews (Taxus) the leaves are flat, but in some related 
genera they are scale-like. 
Laboratory Studies. (a) In the spring of the year collect a 
quantity of the microspore (staminate) cones of a pine (Scotch 
or Austrian are very good), and preserve.such as are not wanted 
for immediate use in alcohol. Collect at the same time the 
young megaspore (ovule-bearing) cones which are to be found 
at the ends of the new shoots. 
(b) Split both kinds of cones vertically, and study their 
structure, comparing the one with the other. 
(c) Study microspores from young and mature cones. In 
the young microspores look for the cells representing the game- 
tophyte; in the mature microspores note the bladder-like 
enlargements of the outer coat. 
(d) Study young megaspore cones of different ages, and note 
the growth of the “‘seed scale.” 
(e) Study megaspore cones one year old and note the devel- 
opment of the gametophyte, and later the archegones. 
(f) Note that the megaspore cones of Scotch and Austrian 
pines are two years in coming to maturity. Make vertical 
sections of cones of various ages, and note the growth of the 
seed. Note the thin wing (useful in their dispersion) on the 
seeds. Make longitudinal sections of seeds, and note the 
little sporophyte with its several leaves (cotyledons). 
(g) Examine the very young twigs as they develop in the 
