sl 
\ 
22 BULLETIN 75, U. S. DEPARTMENT OF AGRICULTURE, 
After the flowers from which insects were to be excluded had been 
inclosed in the netting tents, they were examined every day or every 
second day until all of the flowers had become entirely wilted. When- 
ever any flower was found tripped, the calyx was marked with a mix- 
ture of carbon black and water in order that the pod which might 
develop from the tripped flower could be distinguished from any pod 
that might develop from a flower that had not been observed to be 
tripped. The unmarked flowers were observed until they wilted, so 
it is certain that none of them became tripped. - 
Table XIIT shows the number of flowers that became tripped and 
also the number of pods and seeds that developed from tripped and 
untripped flowers. 
TaBLe XIII.—Pods and seeds from self-tripped alfalfa flowers at Pullman, Wash., 1910 
Number of flowers. 
Number | Number Metcan 
ofmature| of pods ALE 
Not aon Seeds from 

Plant. 
















Tri : f 
Total. | and. | tipped | marked | sootkea | “not. | Pods not 
marked. | xed. | | pods. | marked. | 78™*° 
RIGS eee Rip tee re nd 128 9 119 1 0 0| 0 
NO oe tek Nt cata 104 17 87 12 18 4 | 4 
NOON eres ian a 59 2 57 1 0 1 | 0 
Newite eeet, Solr ee 100 15 85 4 3 0 0 
ES Ogee ens ene 62 4 58 0 0 0 0 
S/O, TR ie Sat: eG aS ea 91 1 90 1 1 0 0 
i Lgl RE Os Saas Ld 2 ae 7 3 76 2 4 | 0 0 
Ro 10 ve PRRs a ee | T 71 8 63 0 0 0 0 
CSD Dae 8 sei iy es ae 81 1 80 6 0| 0 0 
WIGLAlIES saat Peewee 1s 775 | 60 | 715 | 21 | 26 | 5 4 
TMOWeTS LEIP pedioe Ja. oi. Soe ee. Us cee eee per cent. . - 7. 74 
‘Tripped, lowers producing pods. 2... 2 at oe eee ee do.... 35.00 
Plowers not iaipped producing pods=.2 2 222-2. 2 ee do-=-) *s09 
Average number of mature seeds per pod from tripped flowers... .-..-- 1, 23 
Average number of mature seeds per pod which developed from flowers 
Hob Observed to be tripped... ose. se eas See ee ee . 80 
Table XIII shows that 7.7 per cent of the flowers observed on the 
nine plants became tripped. In several of the flowers the keel was 
observed gradually to open, and later the flowers were found to be 
tripped. As the tents were made so that honey-gathering insects did 
not have access to the flowers and as care was taken to prevent any 
other object from coming in contact with the flowers, it seems clear 
that the tripping which occurred was automatic. 
Five of the 775 flowers observed produced pods, when no evidence 
that these flowers had been tripped could be found. It is possible 
that three of these flowers may have become tripped without being 
observed or that the carbon which was placed on the calyx may have 
been removed. However, two flowers were found in which the pod 
was developing and the tip of the young pod was protruding through 
