136 



Prof. Farlow saw only hive-bees collect nectar on 6". nodosa (Grav, i, 

 p. 151). Meehan finds S. canina visited by "small sandwasps 'and 

 other winged insects "(i, 108). Dr. Gray states that S. nodosa is 

 visited by hive-bees (2, p. m ; 3, p. 36 ; 4, p. 220); and Darwin 

 quotesthis statement (3, p. 424). Wilson observed a wasp while 

 collecting nectar from S. nodosa, and quotes Miiller and Darwin on 

 the visits of wasps to th's species and to S. aquatica (i, pp. ^e^-dS 

 Delpino finds wasps on the flowers in Italy (i, p. 212), and Lubbock 

 also speaks of their visits (i, p. 137). Finally I have observed 

 Jiumenes fraterna and Odynerus albophaleratm collecting nectar from 

 the flowers several times in New York, New Jersey and Wisconsin, 

 and small bees belonging to ti^'o or more species of Halictus were 

 occasionally noticed similarly employed. The former cling to the 

 flower inserting only their heads, as Sprengel and Miiller have shown 

 to be the case with the larger wasps ; the latter creep bodily into 

 the corolla. Both are forced by the shape of the corolla and the 

 presence of the arched fifth stamen to enter in the median line 

 Ihe nectar is also attractive to certain large ants, which were they 

 more active, would give efficient aid in the transfer of pollen from 

 flower to flower; their sluggishness, however, renders their services 

 of little value and, as they seldom travel from plant to plant, the 

 crossing they do fefTect is merely between flowers of the same stock. 

 1 he flowers are also sometimes visited for their pollen ; Sprengei 

 found ' em Insekt welches eine Aehnlichkeit mit einer Biene und 

 auch einen Stachel im After hat, aber viel kleiner ist, als eine "Biene 



(probably a Halictus\ ensratjed in roHprf-mo- r-nllAr, frr^r>. 



\ 



Halictus 



S- nodosa 



manner; and near Madison I had an opportunity to watch a species 

 of the_same genus as it collected pollen. From the ;.hnv^ ctnf._ 



ments it appears that the nectar of Scrophtdaria is attractive to wasps 

 bees, and ants, principally the first-mentioned ; and there is every 

 reason for believmg that the entire genus is adapted to profit especi- 

 ally by the visits^ of these insects, which appear to find the nectar 

 more palatable than do bees. As in Symphorjcarpus racemosus and 

 Rtbes Cynosbatt,'' which are also largely visited by wasps, and also 

 have corolla tubes of comparatively little depth, Scrop/iularia 

 nodosa IS occasionally perforated (Sprengel, ]. c, p. 324), afd here, 

 as there the depredator is, no doubt, one of the larger species of Vesfia 

 though direct observation has failed to discover its identity as yet ' 

 Sprengel saw that insects must transfer pollen from' older' to 

 younger flowers while gathering nectar, and that the result was 

 M^^t ^"^not close-fertilization ; and most later observers agree 

 with him._ Mr. Wilson is, however, the first who has tried to show 

 how the inconspicuousness of the flowers and ih^ protero^yny areTf 

 value tathe plant (i, p. 565), both being correlated^with thTidapta 

 \i H f ^ fl^^^'-^ '^ ^'^^Ps, these partly predaceous insects bein. 



Httt diffi'cultr I1? W-r ^\'!"°^" inc'onspicuous oblects S 

 little mtticulty Mr. Wilson believes, and rightly that a flower 



adapted to fertil ization^t^ their agency ca nj^ach L hfghes[ 



* Bulletin Torrey Club, June. 1881, pp.~68^ 



