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The Aroids have some interesting points in their 

 raceae. pollination. Some of the speoies are dull in 

 color as our Jack-in the Pulpit. 



Avoids. In Arum tnaculation The "flower" con- 

 sists of a green leaf called the spathe which contains a central 

 portion, the spadix, that bears the flowers. The pistils are 

 near the base, while the stamens are higher up. Lubbock 

 says: "Now in this case nothing would at flrst sight seem 

 easier or more natural than that the pollen from the anthers 

 should fall on and fertilize the pistils." In this case the 

 stigmas mature before the pistil — p roterogyno us. Small 

 flies (several hundred have been found in a single flower), 

 which are attracted by the showy spaddxenter the flower and 

 and are imprisoned by the stiff hairs which line the spathe. 

 They have, however, left some pollen on the ripe stigmas. 

 After the period of maturity has passed, each stigma secretes 

 some nectar which repays the insect. The stamens then 

 dehisce, the pollen drops to the bottom of the cavity, and the 

 insects become covered with pollen. The hairs on the spathe 

 now shrivel up and the insects are released. In Arum 

 concephaloides the structure of the inflorescence is some- 

 what similar. The insects seek shelter in the "flowers," 

 which are somewhat warmer than the surrounding atmos- 

 phere— 302_to__36° Cent., while in Arum Italicum the 

 temperature has been observed at 44® Cent. The flowers of 

 this and other aroids have a disagreeable odor, not unlike 

 that of decomposing urine. It therefore attracts insects that 

 seek such odors, which find the flattened expansion of the 

 spathe a convenient landing place. In the narrow portion of 

 the spathe a ring of stifl hairs projects horizontally except the 

 tips, which bend downward, making a perfect ring. A 

 second ring occurs just above the pistils. These shrivel up 



