1905] COULTER & LAND—TORREVA TAXIFOLIA 163 
tion of the strobilus, with its investing vascular cylinder, may be 
observed, apparently an important storage region for the strobilus. 
STAMENS.—At the stage of the stamineal primordia observed 
August 12, there is no evident differentiation of tissues (fig. 8), but 
early in September the young sporangia become distinct, the sporo- 
genous tissue being represented in each case by a single primary 
sporogenous cell. At this stage the further development of the 
young sporangia differs. Seven sporangia are seen in the primary 
sporogenous cell stage, three adaxial and four abaxial (jig. ro), 
radially arranged about the central axis as are the five or more spor- 
angia in the allied Taxus. The four abaxial sporangia develop in 
the usual way, and become the pendent abaxial sporangia character- 
istic of Torreya. The three adaxial sporangia, however, do not 
develop further, the primary sporogenous cell not dividing, and its 
nucleus showing signs of disorganization (fig. 9). The disorganiza- 
tion continues until it involves all the cells separating the three adaxial 
sporangia, which are thus replaced by a single large flattened cavity, 
which becomes a resin cavity. Intermediate stages were found in 
which the three sporogenous regions were still distinct (fig. 10). In 
jig. 11 (October 21) is shown a median longitudinal section through 
a stamen, in which the large resin cavity is seen above and the nor- 
mally developing sporogenous tissue below. As a result, the mature 
stamen of Torreya is characterized by four abaxial sporangia and a 
large adaxial resin cavity. 
In one instance the two lateral sporangia were smaller than the 
middle ones (fig. ro), suggesting a tendency to still greater reduction 
in the number of sporangia. Accordingly Pinus Laricio was exam- 
ined, and two resin cavities were found related to the two sporangia 
exactly as the two lateral sporangia of T ‘orreya are to the middle 
ones; and in early stages the tissue on the sites of these two resin cavi- 
ties of Pinus resembles that of sporangia. It is interesting to note 
that in T. californica Miss ROBERTSON (8) found occasional stamens 
bearing six or seven mature sporangia, indicating that in these cases 
some or all of the usually abortive sporangia reached maturity. 
There is evident a tendency to reduce the number of functioning 
sporangia by abortion, a reduction that has proceeded farther in 
Pinus than in Torreya; and in the latter farther than in Taxus. That 
