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AMERICAN JOURNAL OF BOTANY 
[Vol. 9. 
vulgaris all seven flowers used opened their stigmas 20 to 65 minutes after 
forcible pollination. In Mimulus glahratus var. Jamesii the eight stigmas 
which were pollinated and closed subsequently opened, four of them within 
30 minutes, and the other four probably in about the same time, though 
observation was not made till 10 hours after the first closing, when the four 
were all wide open. Having but a few flowers of Mimulus punctatus, I 
used but one stigma for the present purpose. This stigma opened 10 
minutes after forcible pollination. In the species Mimulus cardinalis 
nine forcibly pollinated stigmas were observed for subsequent behavior. 
Eight of these stigmas opened in periods ranging from 20 to 150 minutes 
after closing, the earlier opening taking place in a temperature of 28.5°, 
the later in 12.5°. The plant used was in the open garden and was pro- 
tected from insects by a cheesecloth net. In the species Torenia fournieri, 
twenty stigmas were forcibly pollinated and closed. Eleven opened in 
20 to 70 minutes, and nine remained closed. This is the same species used 
by Burck (12) and found by him to keep its stigma closed with dry pollen 
and to open the stigma after moist pollen was used. In my hands the 
stigmas of this species opened after using either dry or moist pollen; but I 
shall return later in this paper to the matter of the influence of moisture on 
closing. Twenty-seven flowers of Tecoma radicans were observed for the 
behavior of forcibly pollinated stigmas. Twenty-six of these stigmas 
remained closed and only one opened. In the species Catalpa bignonioides, 
89 stigmas were observed after being pollinated and closed by the pressure 
stimulation. Some of these tests were made in sunshine and some in shade, 
some in dry air and some in moist, and in temperatures from 18° to 32°. 
The general summarized result gives 39 stigmas opening after the first 
closing and 50 remaining continuously closed. In very moist air, the 
most of the pollinated and closed stigmas of Catalpa and Torenia will 
reopen . 
Inasmuch as none of my experiments here recorded were given conditions 
that might not obtain in nature, it follows that the stigmas of all my seven 
species tested may reopen in appropriate natural conditions, after their 
closing at the time of pollination by the usual natural agent. One may 
believe that not only these seven species and the Diplacus, as found by 
Lloyd (14), but also all the other related species known to have sensitive 
stigmas may at times show their stigmas opening after the first closing, 
and subsequently closing again. These relations are justification for 
speaking, as in this paper, of primary and secondary closing of the stigmas. 
As the primary closing of stigmas, even when pollinated, is in Utric- 
ularia vulgaris and Mimulus glahratus generally, and may be in other 
species not infrequently, followed in 15 to 60 minutes by opening, it is 
necessary to assume that the biological significance of the primary closing 
is likely to be some immediate good in the life of the plant. F. Miiller (4), 
Hildebrand (5), Batalin (6), H. Miiller (7), Darwin (9), and Elrod (13) have 
