HAY-TIME 149 



between the knots are at this time very short, and at 

 first the leaves and their sheaths grow faster than the 

 sections of the haulms, so that they greatly exceed 

 them in length. One result is that the sheaths over- 

 lap, and a cut across a young haulm may show several 

 sheaths, one inside another. The leaves borne on the 

 haulm are profitable to the plant in the early season, 

 and they attain a fair length in April or May, but the 

 haulm itself is then quite short. It does not rise to 

 any considerable height until the flowering-time is 

 close at hand. Till then unusual height would bring 

 with it the risk of laying by the wind and rain, and 

 no corresponding advantage. 



But when the flowers are ready to open it is 

 necessary that they should clear the low herbage. 

 The pollen, and a little later the seeds, have to be 

 dispersed, and this is best effected when they are 

 carried on tall, elastic stalks which dance in the wind. 

 The haulm, which was short and succulent, now 

 rapidly expands, shooting upwards and enlarging in 

 diameter at the same time. A haulm of a certain 

 grass, Festuca elatior, which I measured from day to 

 day, lengthened two inches in twenty-four hours 

 during part of the time. The growth is so rapid that 

 the cellular tissue in the interior tears open, and the 

 haulm becomes hollow. There is comparatively little 

 increase of weight, chiefly expansion and hardening 

 of tissues already formed. The sections of the haulm 

 increase in length till they equal or a little exceed the 

 leaf-sheaths, and these, which were telescoped one 

 within another, now become drawn out. It is not 

 uncommon to find the terminal joint very much pro- 



