530 THE FERTILISATION OF FLOWERS. [rarr IL. 
of this plant for more than an hour. I was able to watch about 
twenty plants simultaneously, and on each three or more insects 
were often busy sucking honey together. I concentrated my atten- 
tion in every case on a single insect, and did not catch it until it had 
accomplished at least one act of fertilisation ; most of them I only 
caught after they had fertilised three, four, or more flowers. The 
specimen of Grammoptera levis which I have figured (4, Fig. 178) 
was already laden with pollinia when I first noticed it; it visited 
‘six flowers in my presence, carrying off the pollinia from four, and 
applying pollen to the stigmas of the other two, which had been 
Fic, 178.—Listera ovata, R. Bz. 
1.—Portion of an unfertilised flower, from the side. 
2.—Front view of flower, after the pollen masses (po) have been removed from the anther. The 
flat rostellum (r) is bent forwards, and partly conceals the stigma (st). (Magnified one half as much 
asl.) mn, nectary. 
8.—Pollen-masses adhering to a needle (x 20). k, cement; po, pollen-masses. 
4.—Grammoptera levis, with a number of pollen-masses on its head. 
previously visited and deprived of their pollinia. To judge from 
the number of hardened cement-disks which this insect carried 
upon its head, it must have fertilised very many flowers before I 
began to watch it. Although a great many insects flew away 
before I tried to catch them, and others escaped me, I secured a 
considerable number, all of which I had seen effecting cross-fertil- 
isation, and all of which still bore pollinia on their heads. Except 
Grammoptera levis* they were all Ichneumonide. They have been 
identified for me by Dr. Kaltenbach of Aachen as follows: (1) 
Ichneumon uniguttatus (one specimen); (2) Alysia (one); (3) 
1 Sprengel seems to have caught this insect bearing pollinia of Zistera ovata. 
At least he mentions a small beetle with black head and scutellum,and brown elytar. 
