46 D. P. Penhallow — Tendril Movements in 



Being unable at present to give further attention to the in- 

 vestigation of the internal structure and peculiarities of this 

 meteorite, it has been transferred to Mr. Geo. F. Kunz, who 

 will probably have it cut up for investigation and distribution. 



Mill Rock. New Haven, Oct. 1, 1885. 



Art. VI. — Tendril Movements in Cucurbita maxima and C. Pepo / 

 by D. P. Penhallow. With Plate V. 



In the summer of 1874, certain experiments were made with 

 reference to the mechanical energy with which the organization 

 of tissues is effected, as illustrated in the lifting power of the 

 mammoth squash.* During the same and following years, as 

 suggested not only by these experiments, but more particularly 

 by Darwin's paper on Climbing Plants in the Journal of the 

 Linnean Society for 1865, I undertook to study the movements 

 of the squash tendrils and terminal bud, and trace the relation 

 of these phenomena to meteorological and other conditions of 

 growth, in order to determine if possible, a rational solution of 

 a question at that time not at all well understood, except in its 

 more external aspects, as studied by Sachs, De Vries and Dar- 

 win. At that time it was recognized that plants possess no 

 nervous system, yet phenomena were continually observed 

 which were wholly inexplicable upon any other ground than 

 that the plant must possess something akin to nerves. At 

 that time also, it was regarded as fully demonstrated that each 

 protoplasmic mass of a cell is a unit within itself, its limita- 

 tions being determined by the surrounding cell wall. 



The observations which I then made upon tendril movement 

 have never been published, though the results were fully 

 worked out five years since. Publication was withheld in the 

 hopes that at no distant day, the correct solution of certain 

 phenomena, which could not then be satisfactorily accounted 

 for, might be reached. 



The very important discoveries of the past few years, touch- 

 ing the continuity of protoplasm, served to give a clue which has 

 been followed up during the past summer with the results 

 that the true explanation of the tendril movement in Cucurbita 

 and possibly also in the whole family Cucurbitacece 1 appears 

 to have been reached from histological research, and we now 

 feel justified in presenting the facts obtained, more especially 

 as they will doubtless tend to enlarge an already rapidly 

 widening field for observation. 



* Phenomena of Plant Life: Clark. 



