182 



POPULAE SOIEIsrCE NEWS. 



[December, 1889. 



that plants coming from seeds which had been 

 " cross-iertilized," that is, influenced hy pollen from 

 another plant of the same kind, were hardier and 

 more vigorous than those which had been " close- 

 fertilized" or influenced hy pollen from the same 

 individual. Thus among the numerous plants 

 ui»n which Mr. Darwin experimented were two 

 sets of horse-shoe pelargoniums, all of the same 

 age, but with the difference that one lot was com- 

 posed of plants raised froin cross-fertilized seeds, 

 while the others were all from seeds which had been 

 close-fertilized. When the plants were well grown, 

 careful measurements showed that those from cross- 

 fertilized seeds were on the average a third taller 

 than the others, although all had been grown under 

 precisely the same conditions. To find out which 

 set were the hardier, they were all cut down close to 

 the ground and of those which recovered, the pro- 

 portion was as three to two in favor of the plants 

 raised from cross-fertilized seeds. 



Here then is the secret of the flower — its elabor- 

 ate structure is all for the purpose of producing 

 cross-fertilized seeds, so that the ofl"spring may be 

 as vigorous and hardy as possible — and we have 

 now to see how this cross-fertilization is accom- 

 plished. 



In the first place it must be observed that in order 

 to attract insects, it is not enough to have nectar 

 for them, but brilliant colors are necessary to catch 

 their eye and tell them where to come; and in the 

 pelargonium the conspicuousness is much increased 

 by the grouping of the flowers with a cluster raised 

 on a long stem. When a butterfly has come to the 

 flower, it seems to know just where to put its long, 

 slender tongue in order to reach the nectar dow*i in 

 the tube, but there seems reason to believe that the 

 delicate lines usually apparent on the two upper 

 petals, all pointing as they do directly to the open- 

 ing of the nectary, serve to some extent as a guide. 

 The advantage of having the nectar at the lower 

 end of a narrow tube is that it is thereby protected 

 from rain and dew, and kept out of the way of small 

 insects who might otherwise steal it without being 

 of any service in the transference of pollen. If the 

 flower to which the butterfly has come, is one just 

 opened, the pollen-sacs will be in the position 

 shown in Fig. 2, and the stigmas will be concealed 

 and pressed together so that none of the pollen can 



come in contact 

 with them. Un- 

 der these circum- 

 stances the insect 

 in forcing its 

 tongue way down 

 into the nectar 

 tube, must become 

 F'g- '■ well dusted with 



pollen on the lower part of its body, but as long as 

 the stigmas are not exposed, close-fertilization is 

 impossible. As the flower gets older, the pollen- 

 sacs fall ofl", first those near the stigmas and later 

 those of the short stamens, and the stig- 

 mas expand in the very place where the 

 pollen-sacs were at first. If now there 

 comes a butterfly covered with pollen, it 

 cannot fail to brush some on the stigma 

 and so bring about cross-fertilization. 



Immediately after fertilization, pro- 

 found changes take place in all parts of 

 the flower. The petals, stamens, and 

 stigmas, being of no further use, wither 

 and fall off'. The ovary-cells, with their 

 now fertilized ovulets, the styles and the 

 prolongation of the axis which supports 

 them, enlarge and become transformed 

 in a remarkable way to form the beak- 

 life fruit (Fig. 3). When ripe, each style with its 



Fig. 3- 



ovary-cell attached and containing the seed, separ- 

 ates spontaneously from the axis except at the very 

 tip. At the same time the flat 

 style twists spirally, and on the 

 spiral there appear innumerable 

 slender hairs radiating on all 

 sides (Fig. 4). 



If now in imagination we pic- 

 ture the plant growing in its na- 

 tive home, it is easy to see, how 

 at the first breeze the seed's con- 

 nection with the parent will be 

 broken and the little parachute 

 will sail away bearing its precious 

 burden to a new locality, 

 '■'g- 4- At last we may suppose it en- 



tangled in some herbage or stubble. The 

 delicate hairs are readily broken off, so 

 that these cannot long prevent the fruit from 

 falling to the ground, but the interlacing of 

 grass-stems or similar undergrowth may offer a 

 serious impediment, and special means are then 

 necessary to enable the fruit to make its way to the 

 earth. This difficulty is overcome by the following 

 means. The base of the fruit is pointed (see Fig. 

 5) and on the ovary are numerous short stiff" hairs 

 which are all directed upward; let the point of the 

 fruit, therefore, become insinuated into a small 



Fig- 5- 



opening and these hairs will resist its being pulled 

 out. When moistened the spirally coiled style un- 

 twists with considerable force, and if the upper end 

 should come against something which would hold 

 it, the ovary would be twisted and pushed further 

 into the opening. Upon drying the style coils up 

 again as before, but a withdrawal of the ovary is 

 prevented by the stiff hairs. Upon the return of 

 moisture the parts of the fruit behave as before and, 

 by repeated alternation of moisture and dryness, the 

 fruit finally makes its way to the earth and may 

 even bury itself beneath the surface. 



A LOFTY GARDEN. 

 A BOTANICAL garden has been established in the 

 Alps of Valais at an elevation of more than i;,6oo 

 feet above the level of the sea. It is situated on a cone- 

 shaped knoll, which is about 200 feet high and com- 

 posed of a number of natural terraces, planted with 

 Pinus cemhra and larch, and faces north, east, and 

 west. On the summit is a plateau facing the south, 

 on which will be a little chalet, containing the 

 library and herbarium of the garden. The Associa- 

 tion for the Protection of Plants has bought the 

 land, and converted it into an alpine garden for 

 plants from all the alpine regions of the globe. 

 Representatives of the floras of the Himalayas, of 

 the American mountains, of New Zealand, of the 

 Antartic regions, of the Caucasus, of Siberia, of the 

 Pyrenees, the Alps, the Carpathians, and the Ural, 

 will be separated, and each cultivated in a special 

 division. Naturally, M. H. Correvon was named 

 director of this new trial-garden, in which he had 



already planted several thousand mountain plants. 

 This garden is at so high an elevation that interest- 

 ing observations can be made concerning the floras 

 of all the alpine regions of the globe, on the rela- 

 tions of plants with insects, their acclimatization, 

 variability, etc. Already consignments of plants 

 have been sent to M. Correvon; and a German 

 botanist who is traveling in the East, and is con- 

 tinuing the work of Boissier (M. Bornmuller), has 

 promised some interesting specimens. Other par- 

 cels are expected from Canada, Greenland, and 

 New Zealand. — Gardener's Chronicle. 



GLEANINGS. 



Wood Wool, (Excelsior.)— This material be- 

 gins to be regarded in Europe as the most suitable 

 material in which to pack soft fruits. Imported toys 

 are usually thus packed. The material is soft 

 elastic, cheap. It comeS from the wood of the As- 

 pen Poplar and does not seem to impart its woody 

 smell to fruits packed in it. 



Syringing Plants affected with red spider will 

 help greatly to clean them of this troublesome 

 insect. They cannot live in an atmosphere heavily 

 charged with moisture. This enables owners of 

 greenhouses to control them. When the tempera- 

 ture is up to 90°, the plants, benches, floors, etc., 

 are thoroughly syringed and the house closed up, 

 they retire to other quarters. They like a hot, dry 

 atmosphere. 



A Curious Egg. — It is something unusual to find 

 the white of a fresh, hard-boiled chicken egg colored 

 red, after taking off the shell. The discoverer of 

 such an egg presumed that he had to do with a 

 mirco-organism ; tried to cultivate it, and was not 

 disappointed. A potato substrate was in short 

 time covered with an intense growth of bacillus 

 prodigiosus. We have here a bacillus that not only 

 withstood being boiled for a certain time, without 

 impairing in the least its vitality, but one inside of 

 fresh eggs. 



Where Jerseys Come From.— Jersey Island, the 

 place from which we obtain the favorite Jersey cow, 

 is a small spot of land. If sqnared, it is six and 

 three-quarter miles each way. Yet this little is- 

 land has a population of 60,000 human beings, and 

 has over 12,000 cattle, and has had that number for 

 the last twenty years, for the cencus of 1861 gives 

 12,037, A"<1 ye' they export on an average annually 

 2,000 head. Roughly speaking, on this island they 

 manage to support one head ofkine to every two 

 acres, while in England there is only one head to 

 every ten acres ; therefore, in proportion to its size 

 Jersey exports two-thirds as many cattle every year 

 as England contains. If England were to export 

 cattle at the same rate, her whole stock would be 

 swept away in a single ^ear. 



How TO Tell Good Oats.— Good oats are clean, 

 hard, dry, sweet, heavy, plump, full of flour, and 

 rattle like shot. They have a clean and almost 

 metallic luster. Each oat in a well-grown sample 

 is nearly of the same size. There are but few small 

 or imperfect grains. The hard pressure of a nail on 

 an oat should leave little or no mark. The kernel 

 when pressed between the teeth should clip rather 

 than tear. The skin should be thin. The size of 

 the kernel will be less in proportion than the skin 

 is thick. The color of the oat is not very material, 

 but white oats are generally thinner in the skin than 

 black. Again, black oats will grow on inferior soils. 

 Short, plump oats are preferable to large, long 

 grains. Bearded oats must have an excess of husk. 

 Oats are not necessarily bad because they are thin- 

 skinned or bearded ; but they must contain a less 

 amount of flour per bushel than thin-skinned oats 

 without beards. 



