anrut] THE MECHANISMS OF FLOWERS. 315 
213. ScapiosA CoLumBARIA, L.—This species for the most 
resembles S. arvensis in the structure of its flower, but besides 
_ the five-lobed corolla it presents the following noteworthy differ- 
| nces. In S. arvensis the florets increase in size from the centre to 
he circumference of a capitulum, but in S. Columbaria this 
radual increase is much less marked, though in the marginal 
lorets the lobes of the corolla are large and conspicuous. Thus in 
me specimen, which I examined closely, the tube in the marginal 
lowers was 6 mm. long and 2 to 2} mm. wide at the mouth; the 
xternal lobe of the corolla was 7 to 8 mm. long, the lateral were 
}mm., the internal 2 to 3 mm. _ In the florets of the disk, imme- 
iately contiguous to these marginal florets, the tube was 5 mm. 
mg and 2 mm. wide at the mouth, and the lobes of the corolla 
rere respectively 3, 2, 1; mm. long; finally, in the central florets 
f the capitulum the tube was still 4 mm. long and 1} mm. wide 
the mouth, and the lobes of the corolla were 1 to 2 mm. long. 
n consequence of the smaller size of the central florets and the 
ight increase of size from the centre towards the margin, many 
ore florets find room on equal space in S. Columbaria than in 
S.arvensis. So, although the capitula in S. Columbaria are distinctly 
maller than in S. arvensis, they contain half as many florets again 
eventy to eighty). 
I have never found plants with abortive stamens in S. Colum- 
_ This species only occurs near Lippstadt, in one locality and in 
{ amount, sol have had little opportunity of watching its 
usect-visitors. 
A. Hymenoptera—A pide: (1) Apis mellifica, L. $, s., ab. ; (2) Bombus 
| lapidarius, L. ¢, very freq.,s. B. Diptera-—(a) Syrphide : (3) Eristalis tenax, 
| L.; (4) E. nemorum, L.; (5) Helophilus trivittatus, F., all three species ab., s., 
and f.p. ; (b) Conopide : (6) Sicus ferrugineus, L.,s. A list of Alpine visitors 
(six flies, eight bees, and twenty-eight Lepidoptera) is given in No. 609, p. 400. 
aa Scabiosa lucida, Vill., is visited by butterflies and Syrphide 
(609). 
[= 
Orv. COMPOSITE. 
: ‘The numerical preponderance which this family has attained 
_ M species and genera,! and the extreme abundance of many of the 
| ‘§ pecies, are due to the concurrence of several characters, most of 
 1In Dr. Ludwig Pfeiffer’s Synonymia Botanica over 10,000 genera of Phanerogams 
are enumerated ; of these, over 1,000 belong to the Composite. 
