292 SIGNIFICANT VESTIGES IN 



ders of flying insects more closely into contact with the anthers. 



By thus making itself useful, the fifth stamen of the Pentstemon 

 keeps its place and its importance, while the corresponding organ 

 in almost every other member of the Figwort family is dwindling, 

 or aborted, or has utterly vanished away. 



The Indian Turnip, or " Jack in the Pulpit " ( Ariscema tri- 

 phyllum) is in a state of transition and has nearly become a dioe- 

 cious flower. Prof Gray calls it " by abortion dioecious." The 

 green spathe encloses a glossy spike, around the base of which will 

 be found a group of pistils or a group of stamens. But one Jack 

 in a baker's dozen is a case of atavism, it seems — a reminiscence, 

 perhaps, of some bygone time when all Jacks bore both stamens 

 and pistils. The base of its spadix is surrounded by a group of 

 pistils, with two or three stamens above them, or by a group of 

 stamens, with two or three pistils below them. This arrangement, 

 occasionally referred to, as it were, by the Indian Turnip, is fre- 

 quently adopted by the Green Dragon ( Arisama Dracontium), 

 and is still habitual with the near relations of the Arismma, Pel- 

 tranda virginica and Calla palustris. But the majority of the 

 Indian Turnips are unisexual, and thus in this family we have a 

 distinct series, advancing, by abortion, from a lower to a higher 

 mode of reproduction. 



The atrophy of leaves in parasites is a familiar story. Botan- 

 ists count ten or twelve native plants, representing four widely 

 different orders, which subsist, partially or entirely, on vegetable 

 juices sucked from other plants. 



The Eye-bright (Euphrasia) and the Yellow-rattle (Rhinanthus) 

 are just entering upon a similar mode of life, following the evil 

 example of their first cousin, the Painted Cup ( Castillea), which 

 is a thorough-going root parasite. Eye-bright and Yellow-rattle 

 are known to eke out their rations, now and then, with juices 

 , drawn from the roots of whatever grows nearest, and it is not 

 improbable that there are other plants, as yet untouched by suspi- 

 cion, which feed; partially or occasionally, upon nourishment 

 unlawfully purloined from their neighbours. But this nefarious 

 practice cannot remain long unsuspected, for as soon as a plant 

 forms a habit of parasitism it begins to lose its healthy green 

 colour, and its looks betray it. 



