1904] CURRENT LITERATURE 321 
ideas concerning fertilization. Farmer's phrase “apogamous fertilization” is 
a proper expression of uncertainty in reference to the definite criteria of 
fertilization. —J. M. C. 
TWO PAPERS by Fitting constitute a very valuable contribution to our 
knowledge of the physiology of tendrils. The earlier paper is a quantita- 
tive study of the growth of stimulated and unstimulated tendrils. Special 
attention is given to curvatures resulting from contact stimulus, but those 
resulting from amputation, temperature variation, and mechanical bending 
are also considered. 
The growth of unstimulated tendrils is intercalary, being most intense in 
the basal half and manifesting two distinct phases of acceleration separated 
bya period of diminished rate. Growthis uniformly distributed in the tendrils 
in the first of these two phases, but in the second curvature appears as a con- 
sequence of unequally distributed growth, which is maximum at the periphery 
of the side becoming convex and gradually diminishes to zero at the periph- 
ery of the concave side. 
Especially notable is the author’s discovery of high perception capacity 
associated with low reaction capacity. It has long been known that some 
tendrils react to stimuli applied on any side and others only when stimulated 
on one side. The latter are, however, sensitive on all sides, even though 
unable to respond to stimuli not ventrally applied. This is shown when a 
stimulus dorsally applied inhibits response to one ventrally applied. In such 
tendrils a dorsal stimulus will even inhibit the completion of a curve already 
commenced in response to a ventral stimulus. : 
he stimulation of opposite sides does not appreciably affect growth in 
either uniformly reacting or locally reacting tendrils. The curvature formed 
in response to contact stimulus is after a period of hesitation followed by a 
reverse curve which accomplishes straightening and is regarded by Fitting as 
autotropic. The mechanism is the same in each of these curves, the growth 
of the middle zone being accelerated. This eliminates turgor variation asa 
factor in curvature, especially since the growth of the concave side is not 
actually retarded. ee : 
he correction of artificial bendings mechanically formed coincides in 
Process with formation of curves in response to contact stimulus. Haptro- 
‘ropic curvatures are distinguishable from other tropic curves by the manifest 
acceleration in growth of middle zone. The encircling of a support is accom- 
plished by curves formed in response to a series of contact stimuli. Pro- 
longed contact is not a stimulus to effect an acceleration of growth. Excep- 
ton is taken to Noll’s “ Reizfelder” hypothesis. ; : 
The later paper>s is a further ids a the curves produced in tendrils as 
*“Firtinc, Hans, Untersuchungen iiber den Haptrotropismus der Ranken. 
Jahrb, Wiss, Bot. 38: 545-634. 1903. 
SFirTinc, H., Weitere Untersuchungen zur Physiologie der Ranken. 
39: 424-526. 1903. 
Ibid. 
* 
