20 BOTANICAL GAZETTE [JANUARY 
increase in number toward the center and become most numer- 
ous within the central region. 
SECRETORY ORGANS.—A notable feature of the present fossil 
is the occurrence of numerous large mucilage passages. As a 
rule these structures are much altered by decay and compres- 
sion, but in two instances they were found in a very perfect 
state of preservation (fig. 2). So far as it is at present possible to 
determine, these organs occur throughout the sub-cortical region 
where they are in more or less intimate association with the 
sclerenchyma strands. Elsewhere it is not possible to determine 
the distribution satisfactorily, but, from our knowledge of their 
occurrence in recent plants, it is a fair inference that they must 
also be distributed through the entire body of the fundamental 
structure. 
Measurements of such of these passages as were in a 
sufficient state of preservation for such a purpose showed them 
to have the following dimensions: 155X100u; 205X135p; 
215X145. From these results it is possible to deduce an 
average dimension of 127 192u. From this again it appears 
that these passages may be described as of elliptical form, in which 
the minor and major axes have a ratio of 1:1.5. The very 
great size of these structures, unusual except in a few groups of 
plants, seems to suggest a comparison with both Cycadacez and 
Marattiacez. In structure they are simple. Longitudinally 
they form long tubular passages which traverse the stem for 
great distances. In transverse section they consist of large ellip- 
tical openings bounded by a very regular wall composed of par- 
_enchyma-cells often differing but little from those of the sur- 
rounding tissue. They are more commonly somewhat elongated 
tangentially to the central canal, and by analogy with similar 
structures in recent plants we may infer that they contained — 
active protoplasm. They thus form the secretory cells, or an 
epithelium which is not specially differentiated (fig. 3). A 
comparison of the two canals ( fg. 2) will serve to show, how-_ 
ever, that the secretory cells often’ show little or no deviation | 
Peon she — character of the fun ee ae 
