DEVELOPMENT OF PLANTS 397 



noteworthy that the coloration of the spathe is in singular har- 

 mony with these odors, resembling the hues of putrid meat. As 

 a result of these variations, the lower orders of insects visit these 

 flowers in great numbers and unwittingly serve in the transfer 

 of the microspores; 250 carrion beetles and over 1,000 midges 

 have been reported as taken from a single spathe. You can 

 readily demonstrate that small insects are attracted to the spathe 

 by examining the inflorescence of the skunk cabbage and jack- 

 in-the-pulpit. 



Common Examples of the Arales. — In the skunk cabbage 

 (Spatheyma foetida), which is of common occurrence along 

 muddy streams, the inflorescence may appear as early as Febru- 

 ary, while the leaves are still rolled up into a compact bodkin to 

 enable them to penetrate the soil. Later the leaves unroll and 

 become very large, being good types of aroid leaves with broad 

 blades, strongly net-veined and evidently adapted to abundant 

 moisture and rapid transpiration. The spathe is shell-like, mot- 

 tled with purple, green and yellow and encloses a fleshy oblong 

 spadix that is entirely covered with flowers. You will find that 

 small insects are attracted to these spathes in great numbers and 

 spiders often take advantage of this fact and spin their webs 

 out of sight in the darker recesses of the spathe. In this plant, 

 the flowers are decidedly in advance of those noted in Typha, 

 being perfect, and in addition containing a perianth of four 

 sepals which arch over the sporophylls. The crossing of the 

 flowers is effected in a variety of ways. In some cases the in- 

 conspicuous stigmas first push out from between the sepals so 

 that microspores must be brought from another earlier flowering 

 plant. In other cases, the stamens at the top of the spadix are 

 first extruded and shed their spores while at the bottom of the 

 spadix the reverse condition obtains, the stigmas being in a re- 

 ceptive condition. This might result in a crossing of the upper 

 flowers with the lower, and later, when the lower flowers put 

 out their stamens and the upper their stigmas, insects could effect 

 a reverse crossing. As the seeds mature the spadix and sepals 

 become large and spongy, enclosing the ovaries which are finally 

 set free by the decay of the spadix, as fleshy berries. This fruit 



