Madelitie Carson. 
*So 
of the seedling, particularly of the hypocotyledonary stem, with 
the view of ascertaining whether any portion of its tissues was 
particularly modified to fulfil the function of carbon assimilation. 
I first selected Bruguiera for examination. A transverse 
section about the middle of the hypocotyl revealed the following 
structures (Text-fig. 8). In the centre the pith was well developed 
and consisted of ordinary soft parenchymatous cells. Among these 
were scattered numerous cells with brownish contents. On the 
addition of iron salts these cells became dark green to black in 
colour and evidently contained tannin. At the edge of the pith 
were numerous small vascular bundles, containing only three or 
four xylem elements, and outside these a few phloem elements. 
The vascular bundles were separated from the cortex by a definite 
row of cells which might be regarded as a bundle sheath. The 
cortex contained an anastomosing network of tannin cells, and 
among these were seen many cells which did not stain for tannin, 
but contained abundance of starch grains. There were very 
numerous intercellular spaces, that is the cortex was lacunar, 
resembling in general character the aerenchyme tissue in the 
older breathing roots, although the aerenchyme tissue was not 
developed to such a marked degree. In sections stained with 
methylene blue the tannin containing cells made a conspicuous 
network. Other sections were stained with methylene blue and 
safranin. In these sections it was found that the tannin cells still 
took the methylene blue stain and made a ramifying network, while 
the protoplasmic contents of the other cells stained red. 
Boiling unstained sections in water in order to dissolve out 
the tannin, very curiously turned the cells pink, so that even in an 
uncoloured section the course of the tannin containing cells 
and starch containing cells could be traced. The hypodermal 
cells were small, while the epidermal cells were large, 
elongated and contained tannin. In longitudinal section these 
tannin cells could be seen in definite strands which branched and 
anastamosed throughout the length of the stem. As one would 
naturally expect to find in a xerophytic plant the cuticle was very 
thick. 
For a long time I was unsuccessful in finding either stomates 
or lenticels, or any place where air could enter the tissues. 
Removal of a complete plant from alcohol to water and 
examination under a strong lens, showed that drops of liquid 
exuded from the plant, in certain definite lines along its whole 
