The Seniors of the Forest 293 



covered by the seed-coat. From three to five of 

 these little flasks are prepared for pollen in each 

 of the pine-ovules. 



At the season when the winds are freighted with 

 the pollen of the cone-bearers the scales of the 

 pistillate flower draw apart, so that the precious 

 dust can slip down between them to the ovule. 

 And just at this stage of affairs a tiny drop of 

 fluid exudes from the opening in the ovule's coat. 

 The golden grains brought by the breezes are 

 caught and held in this, and as the fluid evap- 

 orates, or is absorbed, they are gradually drawn 

 down to the ovule's surface. 



The ripe pollen-grain of the pine is not a mere 

 bag of jelly, as is the pollen-grain of the crocus. 

 It has two compartments or " cells" like the 

 smaller spore of the selaginella. One of these is 

 merely vegetative, and one, a little later, develops 

 into the pollen-tube. The tube put forth by the 

 crocus pollen grain contains one globule of vitaliz- 

 ing protoplasm, the " generative cell." But the 

 perfected pollen-tube of the pine contains two gen- 

 erative cells. 



The tube penetrates the tissue of the ovule for 

 a very short distance, and then there is a pause, 

 while the little archegonia down below are coming 



