1905] COULTER & LAND—TORREYA TAXIFOLIA 173 
The inner layer of the inner integument comprises several layers 
of thin-walled cells, but beyond the integuments it is not histologically 
differentiated as a layer distinct from the tissue within. Accordingly, 
through the great bulk of the seed this layer may be neglected, and 
the whole mass of tissue within the stony layer and outside of the 
embryo sac will be spoken of as nuclear tissue or perisperm. 
The behavior of the endosperm is peculiar, resulting in what is 
called “‘ruminated endosperm,” a phenomenon peculiar to Torreya 
among gymnosperms, and commonly illustrated by the nutmeg. 
‘“Rumination” of endosperm proves to be a misnomer, for the endo- 
sperm is always the successfully aggressive tissue in developing this 
condition. The perisperm continues to grow throughout the matur-- 
ing of the seed, and the final condition results from what might be 
called the struggle of two growing tissues that have been abutting upon 
one another through their whole period of growth. 
In ordinary seeds the endosperm invades the surrounding tissue 
more or less uniformly; in the case of Cycads and Ginkgo, for exam- 
ple, obliterating most of the perisperm. In Torreya, on the other 
hand, the invasion by the endosperm is irregular in the extreme. 
It is in the season after the proembryo has been formed that the active 
invasion of the perisperm begins. The extension of the endosperm 
into the tip of the nucellus above the sac proceeds in the usual way, 
obliterating all of it except a few peripheral layers of cells. This uni- 
form invasion seems to be due to the fact that in this apical region 
(the original nucellus) the perisperm is not growing actively if at all. 
Below this small region at the tip, however, the perisperm is very active 
and evidently resists disintegration much more at certain points than 
at others. As a consequence, the perisperm becomes eroded by the 
irregularly advancing endosperm, and is left in the condition of a much 
dissected coast-line (figs. 4 and 5). To the casual observer this results 
in an appearance suggesting that the endosperm is being invaded by 
plates of perisperm, but this is no more true than that the promontories 
of a dissected coast-line are advancing into the sea. The suggestion of 
an invading perisperm is further strengthened by the fact that within 
the perisperm bordering the endosperm a dark brown and finally 
black band of cells is developed, due to abundant food storage (jigs. 
4; 30, 31), but this really recedes as the endosperm advances. 
