124 ELEMENTARY STUDIES IN BOTANY 



visible to the ordinary observer, for they are living, like in- 

 ternal parasites, within structures of the sporophyte. 



The female gametophyte. The large,, solitary megaspore 

 within the ovule develops within itself the female gameto- 

 phyte, which consists of numerous cells (Fig. 98, B). Cells 

 on the side of the gametophyte towards the tip of the nucel- 

 lus, which means also towards the micropyle, develop 

 archegonia (Fig. 98, B), and in each archegonium, of course, 

 there is an egg. It becomes evident now that an " ovule " is 

 very far from being an egg, although it received its name be- 

 cause it was thought to be an egg. It is helpful in fixing the 

 relations of parts to remember that the egg is in an archego- 

 nium, the archegonium is produced by the gametophyte, the 

 gametophyte is within the megaspore, and the megaspore 

 is within the ovule (megasporangium) . Of course the egg 

 is passive and remains in the archegonium, awaiting fertiliza- 

 tion. 



The male gametophyte. The microspores (pollen grains) 

 do not remain within the microsporangia (pollen sacs), 

 but are discharged and are widely scattered by the wind. 

 When the pollen of pines is being shed, the air is sometimes 

 full of the small " grains " (spores), which look like yellow 

 powder, and they settle down like rain. In the pines, the 

 pollen grains have wings (Fig. 97, Z>), but this is not true of 

 all Conifers. Of course very few pollen grains land on the 

 right spots, but there are so many of them that some reach 

 the proper landing places. The " right spots " are the ovulate 

 cones, whose hard megasporophylls (carpels), often called 

 the " scales " of the cone, have spread apart to receive them. 

 The minute pollen grains slip down the sloping scale and col- 

 lect in a little drift at the bottom, around the projecting 

 micropyle. Then some of them get into the micropyle and 

 reach the tip of the nucellus, which is their destination. This 

 transfer of pollen from the pollen sacs (microsporangia) 

 to the ovulate cone, and in the cone to the tip of the nucellus, 



