240 Evans: AIR CHAMBERS OF GRIMALDIA FRAGRANS 
section, cut immediately below the epidermis, and seems at first 
to belie his statement. The figure shows the partitions, almost 
complete, of an air chamber, the cells being distinguished by stip- 
pling. Only one end of the chamber is represented; the other end 
did not show because the section was slightly oblique in that 
region and passed through the epidermis instead of the green 
tissue beneath. That the stippled cells represent the boundaries 
of a chamber is evident from their close union and also from the 
b 
Fic. 3. Section parallel with the surface, just below epidermis, X 270. 
Fic. 4. Section a short distance below the one shown in Fic. 3, X 270. 
fact that an epidermal pore was situated above the middle of the 
space which they enclose. It will be seen that the chamber con- 
tains a number of cells, circular in section and either entirely free 
or else loosely connected with one another or with the cells of the 
partitions. Similar cells are shown elsewhere in the figure, and a 
superficial examination would interpret them as the sections of 
filaments, especially if they were considered in connection with 
Fic: 1. 
The incorrectness of this interpretation is brought out by a 
comparison with Fic. 4, which shows the same chamber at a 
lower level, the cells of the partitions being again indicated by 
stippling. In this figure the complete boundaries of the chamber 
