CHAPTER VIII 



for tempting animals to eat the fruits. Sometimes the seeds are not 

 swallowed but are thrown away, more often they pass through the 

 alimentary canal. Many experiments have been made to determine 

 to what extent seeds of fleshy fruits are injured by the digestive 

 fluids ; only the most general results can be stated here. Seeds 

 swallowed by birds are retained only a short time, from one-half to 

 three hours, and a small percentage only are injured ; on the other 

 hand, more than half of those swallowed by animals are rendered 

 incapable of germination. That some poorly protected seeds like oats 

 and barley, escape injury is evident to everyone who has used fresh 

 stable manure as a fertilizer. If fleshy fruits are not eaten, but simply 

 fall to the ground, the decaying fleshy part anchors the seeds to 

 the soil. 



To return to the topic in hand, the awakening of the trees : Young 

 figs appear with first leaf buds, early in the year. The pistillate 

 flowers in the interior can be readily discerned. The pollination of 

 some kinds of figs is described by Kerner in Vol. II, page 159-160, of 

 his " Natural History of Plants." Briefly, the story of our common 

 species is .this : One tree bears edible figs, containing only pistillate 

 flowers ; another tree of the same species bears what are called capri- 

 figs, having near the orifice staminate flowers, but farther up, gall 

 flowers, i. e., undeveloped pistillate flowers in which the egg of a 

 wasp has been placed. The female wasps in escaping from the capri- 

 fig become covered with pollen ; they pass at once to younger figs to 

 lay their eggs, and if they chance to select a tree bearing figs with 

 developed pistillate flowers, they of course pollinate them and the 

 seeds become fertile ; the wasp's egg rarely develops in these figs. 

 If the wasp enters caprifigs, her eggs will develop in the imperfect 

 pistillate flowers, but the caprifigs fall off before becoming juicy 

 Kerner states that while, in some districts, the caprifigs are culti- 

 vated and hung on the fertile trees to ensure pollination, this is quite 

 a waste of labor, for the flavor of the figs is not in the least improved 

 by fertilization ; and, since figs are now propagated by cuttings, it 

 matters not at all that the seed is infertile. 



It is unsafe to make any general statements about the habits of some 

 of our introduced plants, especially if they are irrigated. Of Eucalyptus 

 and Acacia, for instance, we have many species that come from very 

 different climates. The point insisted upon is that children be 

 encouraged to watch continuously some tree or trees in the vicinity of 

 the school building, so that their observations can be tested and dis- 

 cussed. A few additional facts about trees will be brought out in 

 Chapter XIV. 



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