80 THE AMERICAN BOTANIST. 



is not so far from the normal as at first appears. In this 

 type of plant, the flower-cluster terminates the main axis. 

 The first leaf below the cluster has been modified into a 

 spathe in the calla, but in the nearly related golden-club 

 {Oronticum aquaticum) the spathe is hardly perceptible while 

 in the sweet flag {Acorus calamus) it is wholly leaf-like. The 

 calla lily which developed two or more spathe-like organs car- 

 ried the production of spathes a trifle farther than usual, that is 

 all. In this way we can easily account for the double "flowers" 

 of this plant, Jack-in-the-pulpit and the like. What causes the 

 occurrence, however, is still a mystery to botanists. All that is 

 known for certain is that any disturbance of the vegetative 

 processes of the plant is likely to favor it. 



Nutation of Poppy. — The poppy is one of a large 

 number of plants that hang their flower-buds downward until 

 the blossoms are ready to open. In the poppy the young buds 

 form a conventional shepherd's crook, but the flower becomes 

 erect at the time of expanding. Other plants such as the 

 arrow-arum (Peltandra virginica) go through movements just 

 the reverse of this, holding the flower-cluster erect until bloom- 

 ing, but after flowering turning it downward into the water 

 where the seeds are ripened. A writer in a recent number of 

 The Scientific American appears to have slightly mixed his 

 facts on this head, for he says of the poppy : "Once this [the 

 pollen] is received the changes ensuing result in sending off 

 a second signal to the motor zone of the stalk and the cun'a- 

 ture reforms the shepherd's crook which holds the capsule 

 pendulous to drop the seeds wlien mature." It is possible this 

 is the case in Arizona, but in more northern regions, the cap- 

 sule is held stiffly erect, chinks appear in it at the top, just 

 beneath the broad flat stigma, and through these openings 

 the seeds are scattered one by one as the breezes rock the cap- 

 sule on its stem. 



