 parrin.) = THE MECHANISMS OF FLOWERS. 79 
usually a thickened border on either side: and these borders fuse 
below, and at their junction form a little pit which secretes honey. 
Some perfectly formed petals occur, however, in which the honey 
is secreted not by this hollow, but by two smaller pits which stand 
_ to the right and left, on the broader thickened margins (3, Fig. 26). 
In very stunted petals (5 to 7 mm. long, and 3 to 4 mm. broad,) 
_ there is developed upon the inner side of the base a smaller 
lamina, which is fused with the larger for the space of 2 to 3 mm., 
_and has a free portion 1 to3 mm. long. Between the two lamin, 
_ two honey-canals, separated by a fold, are deeply sunk (7, 8, 
_ Fig. 26). Such petals have a striking resemblance to those of 
, Fic, 26. 
; -1~8.—Petals of Ranunculus auricomus. 9.—Petal of EHranthis hiemalis. n, nectary. 
{ Biranthis hiemalis, Between these three varieties we find various, 
often unsymmetrical, intermediate forms, (4, 5, 6, Fig. 26) in which 
‘sometimes no honey is secreted (4, 5). 
After completion of my manuscript I found (April 5 and 20, 1872) the 
_ following insects in flowers of R. auricomus: A. Hymenoptera—(a) Apide : 
(1) Andrena parvula, K. 9, ¢.p. ; (2) A. fulvescens, Sm. ¢,s. ; (3) Halictus cylin- 
_ dricus, Bit: 0.7K $48) Formicide: (4) an undetermined sp., licking honey. 
Bz Diptera—(a) Syrphide: (5) Pipizella virens, F., fp. ; (6) Cheilosia ver- 
_ nalis, Fallen, f.p.; (6) Muscide: (7) Anthomyia shia, Mgn. @ 6, very 
' ab., but so wild that I could not see what it was doing ; (8) Scatophaga mer- 
- daria F., s. and fp. C. Thysanoptera—(9) Thrips, ab. Ants and Thrips 
_ were observed in the flowers by Sprengel. See also No. 590, 1., p. 52. 
Ii. CaLttHa patustris, L.—The honey is secreted by two 
_ shallow depressions on the sides of each carpel, bounded by a slight 
fold. It is so abundant that the drops secreted by the adjacent 
sides of two neighbouring carpels often flow together into a large 
_ drop filling up the cleft between. Anthers and stigmas ripen 
