PINUS LARICIO 175 



through the cotyledons and epicotyl; (c) a cross- 

 section of the seed passing through the hypocotyl. 

 Q. The "Germination" of the Seed: 



1. Observe specimens of seeds and seedlings represent- 

 ing various stages of germination. 



2. Describe (a) the changes that the various parts of 

 the seed undergo, in shape, size, and position; (b) 

 the manner in which the seedling breaks through 

 the surface of the soil, and the advantage of this; 

 (c) the relative rate of early growth of the root and 

 shoot, and the significance of this; (d) color-change 

 in the cotyledons, its significance and whether or 

 not it can take place in darkness; (e) the fate of the 

 endosperm, and the evident r61e of this tissue; (/) 

 the manner of shedding the seed-coat; (g) the place 

 of development and character of any new organs. 



3. Compare the germination of a seed, with that of a 

 spore. What, in reality, is the germination of a 

 seed? 



R. General Questions: 



1. To which alternating generation does the pine tree 

 belong? 



2. In a well- worded paragraph compare the relation 

 of gametophyte and sporophyte in the moss, fern, 

 Isoetes (or Selaginella) t and Pinus. 



3. State the relative prominence of the sexual and 

 asexual generations in plant-groups of successively 

 higher organization. 



4. When the young sporophyte of Pinus begins growth 

 does it grow continuously to maturity, or does a 

 period of rest intervene? Compare it with Isoetes 

 or Selaginella in this respect. 



5. What changes would result in the formation of a 

 seed in Isoetes? What interferes with seed-forma- 



