Page:Life Movements in Plants.djvu/269

 }} I have in the preceding series of Papers demonstrated the effects of various forms of stimuli on growth. I have also given accounts of numerous reactions which are extraordinarily similar, in growing and non-growing organs. In fact certain characteristic reactions observed in motile pulvinus of Mimosa and other ' SBDsitive ' plants led to the discovery of the corresponding phenomena in growing organs. For fully realising the essential similarity of responses given by all plant-organs, growing and non- growing, I shall give here a short review of the striking character of the parallelism.

1. The incipient contraction of a growing organ under stimulus culminates in a marked shortening of the organ.

2. The similarity of contractile responses in growing and pulvinated organs.

3. Similar modification of both under condition of sub-touicity.