n6 THE POPULAR SCIENCE MONTHLY. 



grow, and is cut down when adult, divested of its thorns by a 

 rough process of hacking, and used as food for camels and cattle. 

 It thus provides fresh moist fodder in the African summer when 

 the grass is dried up and all other pasture crops have failed en- 

 tirely. 



The flowers of the prickly pear, as of many other cactuses, 

 grow apparently on the edge of the leaves, which alone might 

 give the observant mind a hint as to the true nature of those 

 thick and flattened expansions. For, whenever what look like 

 leaves bear flowers or fruit on their edge or midrib, as in the 

 familiar instance of butcher's broom, you may be sure at a glance 

 they are really branches in disguise masquerading as foliage. 

 The blossoms in the prickly pear are large, handsome, and yellow; 

 at least, they would be handsome if one could ever see them, but 

 they're generally covered so thick in dust that it's difficult prop- 

 erly to appreciate their beauty. They have a great many petals 

 in numerous rows, and a great many stamens in a rosette in the 

 center ; and to the best of my knowledge and belief, as lawyers 

 put it, they are fertilized for the most part by tropical butterflies ; 

 but on this point, having observed them but little in their native 

 habitats, I speak under correction. 



The fruit itself, to which the plant owes its popular name, is 

 botanically a berry, though a very big one, and it exhibits in a 

 highly specialized degree the general tactics of all its family. As 

 far as their leaf -like stems go, the main object in life of the cac- 

 tuses is not to get eaten. But when it comes to the fruit, this 

 object in life is exactly reversed ; the plant desires its fruit to be 

 devoured by some friendly bird or adapted animal, in order that 

 the hard little seeds buried in the pulp within may be dispersed 

 for germination under suitable conditions. At the same time, 

 true to its central idea, it covers even the pear itself with deter- 

 rent and prickly hairs, meant to act as a defense against useless 

 thieves or petty depredators, who would eat the soft pulp on the 

 plant as it stands (much as wasps do peaches) without benefiting 

 the species in return by dispersing its seedlings. This practice is 

 fully in accordance with the general habit of tropical or subtropi- 

 cal fruits, which lay themselves out to deserve the kind offices of 

 monkeys, parrots, toucans, hornbills, and other such large and 

 powerful fruit-feeders. Fruits which arrange themselves for a 

 clientele of this character have usually thick or nauseous rinds, 

 prickly husks, or other deterrent integuments ; but they are full 

 within of juicy pulp, imbedding stony or nutlike seeds, which 

 pass undigested through the gizzards of their swallowers. 



For a similar reason, the actual prickly pears themselves are 

 attractively colored. I need hardly point out, I suppose, at the 

 present time of day, that such tints in the vegetable world act 



