I02 Cincinnati Society of Natiiral History. 



eral rule, reach across the larger central cavity They proba- 

 bly serve two purposes : first, to allow the passage of air, and 

 second, to act — as suggested by J. Duval Jouve — as supports 

 for the fibro vascular bundles. In a few of the cross sections 



made, the diaphragm was for a distance composed of a single 

 layer of cells, and the remaining portion was divided into two 

 parts or layers. In this manner a cavity was formed with 

 convex boundaries. 



There are in the transverse membranes several cells pro- 

 jecting upward and downward, containing raphides (Fig. i, 

 A). Along with these are cells, containing a secretion, having 

 a reddish color. The.'-e are about the same size as the sur- 

 rounding cells, but they are round. In the membrane or 

 diaphragm there are several lanced-shaped crystals that have 

 broken out of the cells once containing them, and appear as 

 long rods piercing the tissue. 



The closed fibro-vascular bundles (Fig. 2), surrounded by 

 one or two layers of parenchymous cells, have a very definite 

 and similar shape. The position of the constituent cells in 

 regard to each other, is quite regular in the different bundles. 

 In cross section (Fig. 2) they are about twice as long as broad, 

 with the bast tissue at each end extending toward " peculiar 



