eri] THE MECHANISMS OF FLOWERS. 399 
draws its foot forcibly out, it brings with it the corpusculum (g) and 
e two pollinia (7) attached to it by their retinacula (kh). The 
Pp nia stand wide apart when they are extracted (9); but the 
retinacula twist inwards as they dry (cf. 9, 10, 11) bringing the 
pollinia so close together that they may easily be introduced into 
t mother slit. As the insect moves on over the umbel, its foot bearing 
the ae pollinia slips into the lower part of aslit of another flower ; and 
this time as the leg is drawn up the pollinia are left in the pigs 
m E tic chamber opposite to the stigma, since the slit is too narrow to 
admit of their further passage upwards ; and the insect, freeing its 
b oot by a violent pull snaps the retinacula and so. extricates itself. 
‘The pollinia are left behind in the stigmatic chamber, while the 
, r pusculum and its broken retinacula are carried off still firmly 
ached to the insect’s foot. The insect continues its visits, and 
he retinacula attached to its feet now get fixed in corpuscula as 
he claws did before, and an insect’s foot after repeated visits may 
“$01 metimes be seen bearing many corpuscula with their retinacula, 
often dichotomously arranged. : 
_ Delpino saw A. Cornuti in F lorence fertilised in the manner 
yhich I have described by Scolia hortorwm, NS. bicincta, Apis mellifica, 
and Bombus italicus (172, 352). 
__ Ihave observed many bees, wasps, ants, and flies, on the flowers 
of A. Cornuti in Thuringia. Dr. Hildebrand sent me a still larger 
number of insects with corpuscula on their claws, which he had 
‘caught on this plant at Freiburg in the first hot days of July, 
1870. . 
_ The following list comprises the insects observed by Delpino, 
idebrand, and myself :— | 
“Gl Florence, Delpino; F. = Freiburg, Hildebrand ; Th. = 
Whuringia, H. Miller ; | = with corpuscula on -their afters 
A. Pegg ea Apide: (1) Apis mellifica, L. 9! (Fl, Th.) ; (2) 
Bombus italicus, L.! (FL); (3) B. terrestris, L. 8 ¢! (F.) ; (4) B. hypnorum, 
. 1 (F.) ; (5) Halictns Scabiosee, Ill. 9 ! (F.) ; (6) H. cylindricus, id BY 
H. quadricinctus, F. 2! (F.) 5 (8) Several: small species of Halictus (Th.), 
which I never saw caught in the slits ; (9) Ceelioxys sp. 9 ¢! (F.) ; (10) 
Stelis aterrima, Pz. 9 ! (FE); (b) Sphegide : (11) Scolia hortorum, L.! (F1.) ; 
2) Se. bicincta! (Fl.); (13) Sc. quadripunctata, F. 9! (F.); (14) Ammo- 
phila sabulosa, L. 9! (F.) ; (15) Psammophila affinis, K. 9 ! (F.) ; (¢) Vespide : 
16) Polistes gallica, L. 9 ! (F., Th.), and var. diadema ! (Th.) ; (d) Formicide : 
17) Various species (Th.); they got caught in the slits and were not able to set 
emselves free. I‘have never seen an ant tear its leg off in order to escape. B. 
Jiptera—(a) Syrphide : (18) Teens tenax, L.! (F., Th:) ; (19) E. seek 
1! (Th.) ; (20) E. nemorum, L.! (Th.) ; (21) ‘Melithreptus scriptus, L. (Th.) ; 
