2. Reproduction by Runners. (Stolons). Suppose you 

 have put out a good healthy strawberry plant. As soon 

 as it gets a good start the next summer, it will begin to 

 send out some branches from near the point where the 

 leaves and roots come together. These will run along 

 the ground instead of growing straight up. At a distance 

 of several inches from the plant, this runner will put out 

 small roots from its lower side, and leaves will grow from 

 the upper side. These soon take the form of a small 

 strawberry plant connected with the original one. Several 

 of these young plants may start up in a similar way 

 around the parent. For a considerable time these young 

 plants remain connected with the old plant by the runners, 

 but the runners may gradually die as the new plants get 

 roots and leaves enough to support full growth. In time 

 these daughter plants repeat the process. 



An exactly similar thing takes place in one of the molds 

 that we often find on our cultures of bread and similar 

 substances. The spores are borne on branches that grow 

 up into the air, but other branches grow along the surface 

 of the bread, and at the end send root-like processes down 

 into the bread and spore-bearing branches up into the air. 

 In other words, a new plant is produced. 



The runners just described occur at the surface of the 

 soil or the substance over which it is growing. In many 

 plants, such as some of the grasses and canes, the runner 

 passes along beneath the soil, and here and there sends 

 up a new stalk. These may branch underground and 

 thus produce a great number of new plants from one. 



3. Stolons Among Animals. The wonderful animal 

 group of hydroids, some of whose members illustrate 

 budding, also contains forms which send out from the 

 parent special tissues that grow over and attach to the 

 solid support, often very tightly. This serves to hold the 

 animal fast, but this is not all. From this tissue may 

 grow up at various distances, depending on the species, 

 and probably on the nutrition and other conditions of life, 

 new hydroids like the parent. Several other groups of 

 animals somewhat less known have very similar habits. 

 In buds proper there is an actual outgrowing of the body 

 tissues into the bud; in this case the bud, if it is to be 

 called so, arises from the attaching tissue rather than from 

 the body itself. 



4. The Value of Stolons. There is more meaning in 

 this stolon-forming habit than mere multiplication. It is 

 a special method whereby a plant or an animal that has 

 once got hold in a locality that furnishes abundant food 

 for its rapid growth can rapidly take possession of nearby 

 territory, and can spread out more rapidly than if it 

 depended on seeds and spores. This method acts 

 somewhat automatically to adjust the organism to 

 favorable conditions. If the place is not favorable, the 

 parent plant will not have energy to form runners, but will 

 at once produce spores or seeds which may be carried from 

 the spot to a more favorable one. If it is favorable, there 

 will be energy enough for both methods of reproduction, 

 and the organism will take intense possession of the 

 nearby territory as well as scatter spores. Spores lead to 

 wide spreading; runners lead to full possession of a 

 locality. 



4. Tubers. Tubers such as we find in Irish potatoes 

 present a very interesting phase of reproduction. Irish 

 potatoes have seeds and may be propagated by these; 

 but in our cultivation of the potato we do not use this 

 method. From the old plant some stems, not roots, arise 

 and grow under ground instead of coming out as others 

 do. These may grow several inches long in loose soil. 

 At their tips collects food that has been manufactured up 

 in the leaves. This causes them to enlarge at the tip and 

 to form the tuber which we imagine belongs to us rather 



than to the plant. This potato tuber, as every one knows, 

 has "eyes." The eye is merely a bud, and from each one 

 of these eyes a new potato plant may grow. In practise, 

 we cut the potato in pieces and plant the pieces in 

 trenches prepared for them in order to get new plants 

 next year. In nature, the mother plant dies and these 

 potatoes are left free in the ^oil, already "planted." They 

 are not "seed," although we do call them "seed-potatoes." 

 The next spring, when suitable growing weather comes, 

 one or more eyes in each of these will send up a new 

 potato plant. 



There are many plants, especially early spring plants, 

 that store up food in one or several underground bodies, 

 and then die down. This allows multiplication, but in 

 addition it puts the plant's substance beneath the soil 

 where it may better endure the drouth of late summer and 

 the ccld of winter. Also, a new mature plant can spring 

 from these underground stores of food much more 

 quickly than from a small seed. Thus, like the stolon, it 

 is a way of getting quick action. 



5. Reproduction by Leaves. Leaves, with their delicate 

 tender structure, would not seem adapted to reproduction. 

 Yet there are certain fleshy leaves which fall to the 

 ground, and. if moisture is sufficient, they will begin to 

 grow roots from the under side and to send up a little 

 stem from the upper side. In a few plants, as some 

 begonias, one can get a new plant by using a leaf instead, 

 of a twig as a cutting. A very attractive little fern is 

 known as the "walking fern" from a surprising habit it 

 has. It has a simple leaf which runs on into a very 

 tapering, drooping point at its free end. Where this 

 touches the moist ground the tip takes root and a new 

 fern starts. This serves the same purpose as was 

 described for runners. 



6. Division in Many-Celled Organisms. In an earlier 

 chapter we saw how simple plants, such as bacteria, and 

 simple animals, as protozoa, divide into two. It is more 

 difficult to see how a complex animal with special organs, 

 such as mouth, digestive tract, heart, brain, kidneys, and 

 so forth, could possibly divide. Yet this very thing 

 happens quite commonly in animals of the grade of 

 earthworms. It is not true of the earthworm itself, but 

 it is true of other members of the same division of the 

 animal kingdom. 



In worms the division is across the body. Since the 

 mouth, brain, eyes, and other special organs are at the 

 anterior end, these structures must be repeated about half- 

 way back for what is to be the posterior worm. The 

 same is true of the structures that occur at the posterior 

 end. The anterior worm must have a set of these made 

 for him. Of course these new tail structures must lie in 

 front of the new head structures of the rear worm. All 

 these organs usually develop before the two worms 

 separate. We sometimes see four or more such worms in 

 a row, not yet separated, all developed from one worm 

 and soon to break apart. 



In some other types of organisms, as in some of the 

 hydroids, the division is said to be lengthwise. In this 

 case the mouth would be split in two, as would all other 

 such organs. In this way each daughter animal gets one- 

 half of each of the original general organs. 



7. Regeneration of Lost Parts. If a boy cuts a small 

 piece out of his finger, we fully expect the wound to heal. 

 A scar may be formed, but the space is largely filled up 

 and the skin grows over all. This happens so regularly 

 that we do not stop to realize its meaning. It means that 

 lost parts can be regrown. Now we humans could not 

 grow a new arm or even a new finger. We do not have 

 much power of regenerating lost structures, but we have 

 enough to heal wounds. 



