1892. ] | Briefer Articles. 21 
ZT. grandifiorum Salisb. In the first stage, the mouth of the 
licwée:3 is closed by the anthers. Later, the petals expand further, the 
Stamens separate above and the stigmas appear between them, in the 
flower-center. A little nectar secreted by the “septal glands” lies be- 
tween the ovary and filaments as in the preceding species. Hive bees 
occasionally collect the pollen. The stigmas recurving to meet the 
stamens may be self-pollinated in the absence of visitors. 
III. Oakesta tis hae Wats., a tig dear = ean borealis 
Raf., are visited abundan ntly by h e bees nectar con- 
tained in the notoned bases of the Sete naee 
While watching ti pollination of Asters and Solidagos this 
fall, I was surprised to find large numbers of humble-bees, honey-bees, 
wasps, and other large and small Hymenoptera, flies— notably Syrphi- 
dze, beetles and four species of Lepidoptera, visiting So/idago sguar- 
xosa whose flowers were all withered, to suck the nectar secreted by 
the involucral bracts. This is another of the cases of the occurrence 
of the extra floral nectar whose use, if any, to this plant has yet to be 
discovered. ; 
An article in the Biologisches Centralblatt (vol. vim, p. 577) may shed 
some light on the use of these extra-floral nectaries. It is in substance 
this: 
Von Wettstein has observed the accumulation of nectar on the in- 
volucral scales of Jurinea mollis, Serratula lycopifolia, S. centaurotdes, 
Centaurea alpina, &c 
In“ Jurinea the secretion begins when the head has attained one- 
fourth of ifs full development: it ceases when the first flowers unfold. 
It begins each day directly after sunrise, increases until about 8 o’clock 
and then commonly diminishes until evening. Even before sun rise 
one may find ants sitting motionless upon the buds; as soon as the 
nectar-secretion begins they seek most eagerly for the places on the 
Scales at which it appears. Of 250 unopened heads, only ten were 
without ants. . The greatest number on one head was twelve, the aver- 
age three or four. Not seldom they creep over thé flowers so that the 
' purpose seems not to be to exclude them from these. Experiment 
establishes the truth of the theory that the ants, here as in so many 
other cases, are the protectors of the plants—the pigmies, the body- 
guard of the giants, as it were 
Fifty buds were protected against ants by winding their stems with 
wool soaked in camphor-solution and oil. Fifty others were left un- 
touched. After four days all of the heads were examined. Forty- 
seven of the last lot remained; forty-five of them (90 per cent.) had 
blossomed normally; beetles had eaten the involucral scales of two; 
