30 



the cells of the second order of branching rein3.in uninucle- 

 ate. The hasal cell is connected wit!:, the cell on v/iiich it 

 is Lome "b;- an intercellular connectioh of the same t^^e as 

 that v/hich occvrs bet\/een neighboring vegetative cells. 



After they sxe fully formed, tlie hairs elongate great- 

 ly and become hyaline. Each cell takes part in the elonga- 

 tion. A vacuole is formed in the cytoi'la-sm v/hich increa^ses 

 in size as the cells elongate. A very thin layer of cyto- 

 plasm lies bet'./een this vacuole and the cell wall:; in the 

 outer ends of the long cells are seen accuiuulations of cy- 

 toplasm, in v/hich most of the nuclei lie. 



The f\illy formed hairs mi;,y rema,in a considerable time 

 before elongating. Elongation occurs in all the hairs of 

 a single node at the same time, and seems to take place 

 rather suddenly. Tlie total length of a hair of average 

 size before elongation is about 40 >«^ , and after elonga- 

 tion about 550 u/ . Such great increase in size in a short 

 time seems to be rendered possible by the fact that the 

 cells of a hair do not secrete a cellulose v;all until after 

 elongation has teicen place. 



After elongating, the hairs remain for a while on the 

 plfijit, but fintilly the connection bet;/een the basal cells 

 and the vegetative call breaks, and the hairs fall off as 

 a vvhole . ITot infreotientl;- a second crop of liairs is form- 



