POPULAR MISCELLANY. 



429 



is much shortened. With the increase in 

 the amount of fruit, according to Prof. Ar- 

 thur, there is also a corresponding decrease 

 in the size of the vegetative parts of the 

 plant that is, the stems and foliage. A 

 tomato plant grown from green seed in the 

 fourth generation was found to bear three 

 and a fourth times as much fruit as top or 

 stems and leaves together, while a similar 

 plant from ripe seed had only one and an 

 eighth times as much fruit as tops. It fol- 

 lows that, while earliness may be considered 

 as a usual condition in all crops from unripe 

 seed, an increase in the amount of the crop 

 occurs only when the true fruit is the part 

 harvested, as in tomatoes and peas, and a 

 decrease in the amount of the crop occurs 

 when any part besides the fruit is harvested, 

 as in turnips and potatoes. 



Imitative Coloring'of Animals and Plants. 



Among the later papers by Mr. Proctor in 

 " Knowledge " is a study of color-mimicry in 

 animals and flowers. It was suggested by ob- 

 serving a chameleon among the green leaves 

 of an ivy, where it was as green as they. A 

 fly of nearly similar color came along, and 

 was instantly caught by the animal's nimble 

 tongue. Afterward the chameleon settled 

 on one of the sticks supporting the ivy, " and 

 there it gradually assumed the same color, 

 so far harmonizing with the stick that he 

 seemed only an excrescence upon it, not a 

 live creature which a short time before had 

 been light green in color." This incident 

 suggests some other illustrations of various 

 forms in which color affects the development 

 of life. Consider, continues Mr. Proctor, the 

 striped tiger as an example of color in an 

 animal that lives by preying on others, and 

 the zebra as an example of color in an ani- 

 mal whose life depends on its not becoming 

 the prey of carnivorous animals. " We can 

 understand how, in certain regions, those 

 members of feline races who chanced to 

 have markings on their bodies which corre- 

 sponded in appearance with the stems of 

 trees, or with jungle reeds, and the like, 

 would be better able to remain concealed till 

 the animals which formed their prey came 

 within certain range of their spring, and so 

 would have the best chances of living " ; and 

 in like manner it is manifestly to the ad- 

 vantage of the zebra, when sleeping in the 



shade of trees, "to have markings on his 

 body which from a distance would be con- 

 founded with the stems of trees and shrubs, 

 beneath which for a while his active limbs 

 were at rest. For so would he best escape 

 the attacks of animals of prey. It is note- 

 worthy that, when the zebra is stretched on 

 the ground, the stripes on his legs as well as 

 those on his body are vertical as seen from 

 a distance. The same is the case in the 

 tiger's stripes when the animal is coucbed 

 for a spring." Another topic for speculation 

 is the persistency of these imitative charac- 

 teristics, which often appear as sports in the 

 descendants of these animals ages after the 

 purpose of their adaptation has ceased to 

 exist. The author's attention was directed, 

 while he was writing, to a sandy-colored cat 

 " marked with stripes such as hundreds of 

 thousands of years ago were of value to its 

 remote ancestors in the struggle for life " ; 

 and a mule plowing in a field near his 

 house had rings around his legs precisely 

 corresponding to rings on the same parts in 

 the zebra. In the vegetable world, color 

 seems to be in all cases dependent on the 

 requirements of propagation. Thus, where 

 seeds are diffused by animals, as with the 

 berries, we find the fruits brightly colored, to 

 attract the attention of the animal distribu- 

 tors. It will be noticed that, when seeds are 

 distributed by the winds, bright colors are 

 not found in the fruit, even though the plant 

 be closely allied to species distributed by ani- 

 mals in which the bright colors are present. 



Bristling with Fire. Photographic pict- 

 ures of the smoke issuing from the mouth 

 of a cannon at the moment it is fired show 

 thin trails of fire about the circumference of 

 the smoke-cloud, which give its edge the ap- 

 pearance of a porcupine's back bristling with 

 quills. The trails are caused by the ignition 

 of cubes of the pebble-powder which have 

 been shot from the gun before the combus- 

 tion was completed. Prof. W. Mattieu Will- 

 iams has found, by examining the papers 

 of Count Rumford, that he made experi- 

 ments on the same subject, from which he 

 inferred that in the ordinary firing of gun- 

 powder in firearms the explosion must be 

 gradual. In using powder in grains and 

 cubes of sizes proportioned to the caliber of 

 their guns, modern artillerists are only car- 



