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plant is the "'catchfly,'" whose name sug- 

 gests its power. The joints of its stem 

 are long, and near the upper end of each 

 joint is a band of mucilage. This series 

 of sticky bands forms a very effective 

 barrier to any insect trying to crawl up 

 the stem. 



Isolation. — In some cases plants or 

 their flowers are isolated from creeping 

 insects by water, which forms a most 

 efficient barrier. This has been demon- 

 strated by housekeepers, who in the days 

 of "safes" were accustomed to set the 

 legs of the safe in cans of water to ward 

 off the invasion of ants. Of course, plants 

 standing in the water are well isolated, 

 and usually show no further device for 

 warding off creeping insects. There is 

 an interesting fact connected with one of 

 our water smartweeds, which has to do 

 with our subject. Ordinarily it stands in 

 shallow water, and is perfectly smooth ; 

 l3ut when occasionally the water dries up 

 the plant becomes hairy. That this has 

 anything to do with the danger from 

 creeping insects is unlikely, but the hairy 

 covering certainly appears at a very op- 

 portune time. 



The teasel was once extensively culti- 

 vated as a fuller's plant, and one or twQ 

 species of it have become common as 

 wild plants, their dense and prickly flow- 

 ering spikes looking like swabs for 

 cleaning lamp chimneys. The plant is 

 tall and coarse, and is peculiar in that its 

 large opposite leaves unite by their bases 

 about the stem to form a cup. In this 

 way a series of cups is developed on the 

 stem, and in each cup there is water. 

 When a creeping insect crawls over the 

 edge of the cup he sees the stem rising 

 from a pool of water which must be 

 crossed. As there is a series of such 

 pools it is very unlikely that any such in- 

 sect reaches the showy cluster of flowers. 



The so-called "travelers' tree" of the 

 tropics is a teasel upon a larger scale. 

 The enormous flower cluster is at the top 

 of the plant, and between it and the 

 ground is a series of very large water- 

 containing cups formed by the leaves. 

 The popular name has been given by 

 travelers who have been represented as 

 reaching a cup with a spear and piercing 

 it, thus obtaining a supply of water. The 



story is very doubtful, and the water, 

 usually full of the macerating bodies of 

 insects, is still more doubtful. 



Latex. — By this term is meant the 

 milky juice which some plants possess. 

 When such a plant is punctured or torn 

 the latex flows out, and as soon as it is 

 exposed to the air it becomes more and 

 more sticky until it hardens. It is from 

 the latex of certain trees that India rub- 

 ber is obtained, but it may be observed in 

 many plants, notably the milkweeds, 

 which have received their popular name 

 on account of it. 



The milkweed may be used to illustrate 

 how latex may be of service in warding 

 off creeping insects. In many cases the 

 plant is entirely smooth, and the stems 

 of the flower cluster are even slippery. 

 When an ant reaches these slippery sur- 

 faces it clutches for a hold and its sharp 

 claws pierce the tender skin of the plant. 

 Immediately a drop of latex oozes out 

 and becomes sticky, and when the ant 

 seeks to lift its feet there is resistance, and 

 in the struggle the claws clutch deeper, 

 more latex oozes out and becomes more 

 and more sticky, until finally the insect is 

 stuck fast. The flower clusters of certain 

 milkweeds are often found plentifully cov- 

 ered with small captured insects. 



Protective shapes. — Many flowers se- 

 crete their nectar so that a creeping in- 

 sect cannot reach it, but the suitable in- 

 sect can. Illustrations are numerous, but 

 the following will suffice. 



The wild columbine, represented in 

 one of our illustrations, secretes its nec- 

 tar at the bottom of long tubular spurs, 

 which can be traversed by slender pro- 

 bosces, but are impassable to creeping 

 insects. Spurs are developed in many 

 flowers, notably the orchids, and they are 

 always associated with nectar secretion 

 and the visits of proboscis-bearing in- 

 sects. 



In the Pentstemon, a plant whose flow- 

 ers have two lips, as in the Oswego tea 

 in our illustration, but not so prominent, 

 the nectar is secreted in a little ])it. Across 

 the mouth of this pit one of the s'amens, 

 modified for this purpose, is placed like a 

 drop-bar, leaving but a thin crevice lead- 

 ing to the nectar pit. Through this crev- 



