March, 1922] NEWCOMBE — BEHAVIOR OF SENSITIVE STIGMAS 
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movement, the lobes traveling 10° to 15°. The hybrid, in 20 or more 
stigmas tested, showed a larger number of responses, about half the stigmas 
moving 20° to 80°. The stigmas of these plants never close, and the small 
movements noted can be of no benefit to the plant. 
Quite another topic on which considerable work has been done is the 
transmission of stimuli. Meckel (8) simply states that the stimulus is 
transmitted from one lobe to another, without giving his method for de- 
termining such transmission. Burck (12) believed that the stimulus was 
not transmitted in the eight species he worked with. Oliver (10), by holding 
one lobe of the stigma with forceps so that it could not press against the 
other lobe, determined that the stimulus is not transmitted from one lobe 
to the other in Mimulus luteus, but is transmitted in Mimulus cardinalis, 
Martynia lutea, and Martynia proboscidea. Lloyd (14) found the stimulus 
fiot only transmitted from one lobe to the other in Diplaciis glutinosus, 
but not even transmitted from one part to another of the same lobe. The 
stigma of Catalpa hignonioides also shows no transmission of stimulus from 
one lobe to the other, as I have proved many times by using Oliver's method ; 
but in the lobe stimulated, the impulse travels apparently ovei the whole 
lobe from the minute area where the stimulus may be applied. In Mimulus 
punctatus, not many flowers were available for trial, but the six stigmas 
used showed no transmission of stimulus from one lobe to the other. In 
Torenia fournieri there is also no transmission of stimulus from one lobe 
to the other, as I ascertained by numerous tests. 
We may thus feel fairly certain that in some species the stimulus is 
transmitted from lobe to lobe, while in others it is not; and that in the same 
genus, as in Mimulus, one species may show transmission and another 
may not. 
3. Significance of Primary Closing 
It is a matter of common observation that sensitive stigmas of all species 
reopen a few minutes after closing, provided that no pollen is deposited at 
the time of stimulation. The behavior of pollinated and closed stigmas has, 
however, been described by very few authors. Burck (12) states that all 
of the eight species he worked with, except Torenia fournieri, kept their 
stigmas continuously closed after first closing at the time of pollination; 
and Torenia stigmas remained closed if the pollen used on the stigmas was 
dry. Elrod (13) found the pollinated and closed stigmas of Tecoma radicans 
nearly always remaining closed, and always remaining closed if fertiliza- 
tion ensued. On the other hand, Lloyd (14) records the stigmas of Diplacus 
glutinosus as opening regularly, shortly after forcible pollination, to close 
again permanently some hours later. 
In all of the seven species whose stigmas I have tested for opening after 
forcible pollination, I have found all the stigmas opening in two species and 
some of the stigmas opening in each of the five other species. In Utricularia 
