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PROCEEDINGS OF THE AMERICAN ACA.DEMY 



their inner side one or two little globular or pear-shaped cells (Dia- 

 gram, B). Bulb-cells we might call these for want of a better name. 

 With a little higher power than is necessary for making out these 



Diagram of a Longitudinal Section of a Tip of C. parvula. 



A, the apex ; B, bulb-cell ; C, cortex ; D, diaphragm ; E, connection between filament and 

 cortex ; F, filament. 



points, one may observe that each filament is composed of a single 

 row of long cylindrical cells united by their ends. There are three 

 or four of these cells to a chamber. The bulb-cell is always in the 

 neighborhood of the middle of the (ilameut cell to which it is attached ; 

 and opposite to it, that is, on the outer side, the filament is usually 

 connected with the cortex, often by means of a short slender cell. 

 The filaments pass through the diaphragms practically unchanged. 

 Usually it is the middle part of the penetrating filament cell that is 

 in immediate contact with the diaphragm, and the ends of two fila- 

 ment cells never meet in the plane of the diaphragm. Moreover, this 

 filament cell that penetrates the diaphragm never bears a bulb-cell, as 

 far as I have seen. I can discover no direct connection between the 

 filaments of one branch and those in the rest of the plant. They 

 merely converge into a small space at the base of the branch opposite 

 the diaphragm of the main stem, and there they end. 



