POPULAR MISCELLANY. 



425 



thought, generally abandoned, even by the 

 psychologists who were most strongly op- 

 posed to materialism ; they found, as Shake- 

 speare's Troilus said, that " we can not fight 

 upon that argument." 



Insects Injurious to Fruit. — In his paper 

 read at the late meeting of the American 

 Pomological Society on Recent Advances in 

 dealing with* Insects affecting Fruits, Prof. 

 C. V. Riley discusses the methods of com- 

 bating the plum curculio, codling moth, red 

 scale, fluted scale, and other injurious in- 

 sects, giving the results of recent experiments 

 on those insects. He questions whether 

 more injury is done to-day to our fruits than 

 was done fifty or one hundred years ago. In 

 fact, it is patent that with the advances made 

 of late years in our methods of warfare 

 against these fruit pests less injury relatively 

 is done, but, as the area of fruit culture in- 

 creases, so does the aggregate of injury and 

 also the number of species that we have to 

 contend with. He warned pomologists to be 

 on their guard against two foreign insects 

 likely soon to appear in this country — the 

 peach ceratitis, a subtropical insect resem- 

 bling the apple maggot, which is extremely 

 destructive to the peach crop of Bermuda 

 and likely to be troublesome if it once be- 

 comes established in Florida and Georgia; 

 and the Japanese peach fruit- worm, which is 

 allied to our codling moth, and in some sea- 

 sons damages ninety per cent of the peach 

 crop of Japan. He suggested that provision 

 be made for the inspection, at ports of entry, 

 of fruits and plants received from any part 

 of the world from which we know danger 

 threatens. 



Leaves of the Water Lily. — Prof. Miall 

 read a paper in the British Association on the 

 leaves of the giant water lily {Victoria re- 

 gia). He exhibited a photograph of a leaf 

 with a child standing on it to illustrate its 

 flotative power. The leaf differed from that 

 of the English water lilies in that the stalk 

 was affixed almost to the center of it, while 

 the deep slit at the base of the leaf was re- 

 duced to a mere notch, and in the presence 

 of a raised rim. This latter feature was 

 probably not useful for preventing waves 

 breaking over the leaf, as had been supposed, 

 but for preventing one leaf from sliding over 



another. This was proved by the fact that 

 if a leaf was allowed to grow apart from oth- 

 ers the rim bent down and the whole leaf lay 

 flat upon the water. Any solid object touch- 

 ing the young growing leaf would cause the 

 rim to be retained all round. It had been 

 shown, furthermore, that when one leaf slid 

 over another, the portion which was covered 

 degenerated and lost its power of repelling 

 water. The notch at the base of the leaf was 

 formerly supposed, by Prof. Miall himself, to 

 be of service in getting rid of water from the 

 surface, but further experiments had con- 

 vinced him that this was an error. He be- 

 lieved that submergence, the means by which 

 he had previously tested them, was not likely 

 to occur in nature, so he resorted to the use 

 of a garden syringe in order to imitate the 

 effect of rain in filling the leaves. He then 

 found that after fifteen minutes' watering the 

 leaf was no fuller than before and that no 

 water had run out through the notch. On 

 holding the leaf up to the light it was found 

 to be as full of pores as a sieve. The spines 

 with which the leaf was covered were proba- 

 bly a protection against the attacks of the 

 apple snail (ampullaria), one of the chief ene- 

 mies of the plant. When the young leaves 

 were unrolling the spines were so close that 

 no animal could possibly get between them to 

 eat the leaf, and in the full-grown specimens 

 it was only the margins of the rim which were 

 accessible. 



The Future of Water Powers. — In his 



address before the Section of Mechanical 

 Science of the British Association, Mr. H. 

 Cawthorne TJnwin said that in 18*78 Mr. 

 Easton expressed the opinion that the ques- 

 tion of water power was one deserving more 

 consideration than it had lately received, and 

 he pointed to the variation of volume of flow 

 of streams as the principal objection to their 

 larger utilization. Since that time the prog- 

 ress made in systems of transporting and dis- 

 tributing power has given quite a new im- 

 portance to the question of the utilization of 

 water power. There seems to be a proba- 

 bility that in many localities water power will, 

 before long, be used on a quite unprecedented 

 scale, and under conditions involving so great 

 convenience and economy that it may incite 

 a quite sensible movement of the manufac- 

 turers toward districts where water power is 



