314 THE POPULAR SCIENCE MONTHLY. 



here chiefly concerned, are white and perfumed. Now, nothing in 

 nature is without a reason ; and this change of color in the gourd 

 kind from the ordinary normal hue of its race at large is not with- 

 out a sufficient purpose either. I don't know whether most people 

 have ever noticed that hell-shaped or tubular white flowers are 

 almost always heavily scented. Examples familiar to everybody 

 occur in the jasmine, the stephanotis, the gardenia, the tuberose, 

 and the large white tobacco so much cultivated of late in garden- 

 borders. It often happens, indeed, that a plant possesses two al- 

 lied varieties, one of them blue, pink, or yellow, and scentless, 

 while the other is white and deeply perfumed. In these cases, the 

 first kind is a day-flowering plant, while the second opens and 

 spreads abroad its scent in the dusk of evening. One well-known 

 instance exists in England: the red campion or day-flowering 

 lychnis is pink, scentless, and strictly diurnal ; while its ally, the 

 white campion, is beautifully perfumed, and opens its flowers at 

 the sunset only. The reason is that the one species is fertilized by 

 day-flying bees or butterflies, and the other by crepuscular or 

 night-flying moths. Now, in the gray dusk no color can so readily 

 be distinguished as pure white; and lest this peculiarity alone 

 should prove insufiicient to attract moths to the patch of light 

 among the dark foliage, the added attraction of perfume is 

 thrown in gratis by moth-fertilized plants. Such night-flowering 

 white blossoms never possess the spots or lines or colored marks 

 on the petals, which serve as honey-guides in other plants to lead 

 the bees straight to the laden nectary. In the twilight, variega- 

 tion or dapjjling of that sort would be wholly useless. 



The blossoms of the gourds, then, are fertilized by moths, at- 

 tracted to the plant at nightfall by the white corolla and the rich, 

 heavy perfume of the bell-shaped flowers. This perfume is one 

 of a type much affected by aesthetic moths, and not unpleasant to 

 ourselves in the open air, but too cloying for a room, as is the case 

 also with the kindred scent of stephanotis and tuberose. As 

 soon as the flowers have been all fertilized, the male blossoms 

 wither away to nothing ; but the small berry underneath the fe- 

 male ones begins to swell out into a big, round fruit with surpris- 

 ing rapidity. Great heat and much sunshine are of course needed 

 in order to produce this startling result with an annual plant ; 

 and hence the gourd family consists mostly of luxuriant tropical 

 or subtropical species. Their center of origin would seem to lie 

 in India, where species and individuals are still most numerous. 

 Thence the gourds have spread, with gradual modifications to suit 

 climatic changes, to all the hotter climates of the Old and New 

 Worlds. Some of them have reached as far as Peru and the Cape 

 of Good Hope. But very few of them have spread far northward, 

 because a northern climate is ill-adapted for such large and rap- 



