82 BOTANY. 
generally in the form of starch (e.g., the cerea_ grains), 
and sometimes in the form of oily matters (e.g., the seeds 
of mustard, flax, castor-bean, squash, etc.). 
160. The Use of Reserve Material —In the use of reserve 
material, as in the germination of starchy seeds, the starch 
appears to undergo a change exactly like that in its disap- 
pearance from chlorophyll. Here it is certain that oxygen 
is absorbed, and that carbon dioxide is evolved, while the 
starch is transformed into glucose. Similar transforma- 
tions doubtless take place in the use of the starch stored 
up in buds, twigs, stems, bulbs, ete. 
161. In the germination of oily seeds, after the absorp- 
tion of oxygen, starch is (in many cases, at least) first pro- 
duced, and from this the soluble sugar is formed. In any 
case, after the solution is attained the subsequent changes 
are gimilar to those which follow the transformation of the 
starch of the chlorophyll. 
162. The Nutrition of Parasites and Saprophytes is simi- 
lar to that of embryos, buds, bulbs, ete. Here assimilated 
materials are drawn from some other organism, and subse- 
quently undergo digestive changes. In some cases the 
parasitism is only partial, as in the mistletoe, where a part 
of the assimilated matter is formed in the parasite (which, 
therefore, contains chlorophyll), while a portion seems to 
be taken, along with the mineral salts, from the host-plant. 
So, too, there are plants which are partially saprophytic 
in habit, deriving a part of their nourishment as sapro- 
phytes, while the remainder is elaborated by their chloro- 
phyll. 
163. Many cultivated plants, as we grow them, are par- 
tially saprophytic, deriving a portion of their nourishment 
from decaying organic matter in the soil. The so-called 
