220 ANGIOSPERMAEDICOTYLEDONES 



Lepidoptera can insert their proboscis, it being too narrow for that of other insects. 

 It is situated just under the stigma, which projects a little from the upper lip, and is 

 scarcely one mm. long and \ mm. broad. The inserted proboscis of a Lepidopterid 

 first touches the stigma, if dusted with pollen depositing some of this upon it, and 

 after being moistened with nectar takes up a fresh supply when withdrawn, should 

 the flower be in the second stage. The proboscis does not touch the stigma during 

 withdrawal, for its pollen-loaded tip at once sinks down. Automatic self-pollination 

 is excluded. 



Visitors. The following were recorded by the observers, and for the localities 

 mentioned. 



Herm. Miiller (Alps), 7 sp. of Lepidoptera, of which only two possessed a 

 proboscis sufiiciently long to reach the base of the flowers; 10 sp. of humble-bees, 

 which opened the closed ' humble-bee door ' by force ; and a beetle, dvg. the flowers, 

 Schulz, the humble-bee Bombus terrester Z., perforating the flowers and stealing 

 nectar. 



2170. R. minor Ehrh. (=Rhinanthus Crista-galli var. a Z.). (Sprengel, 

 'Entd. Geh.,' pp. 313-15 ; Herm. Miiller, 'Fertilisation,' pp. 455-6, * Alpenblumen,' 

 pp. 284-5; Warming, Bot. Tids., Kjobenhavn, xvii, 1890, pp. 223-6; Schulz, 

 'Beitrage'; Kirchner, 'Flora v. Stuttgart/ p. 600; Knuth, ' Bloemenbiol. Bijdragen,' 

 P- 53') Hermann Miiller, for oecological reasons, concurs with the opinion of 

 Linnaeus that this plant and R. major are merely varieties of one and the same 

 species. The mechanism of the two is actually the same, except that in R. minor 

 the smaller and less conspicuous flowers are not so frequently visited by insects, and 

 are capable of automatic self-pollination. The teeth of the upper lip of the golden- 

 yellow corolla are whitish or violet in colour. The corolla-tube is only 7-8 mm. 

 long, so that even our shortest-tongued humble-bee, Bombus terrester Z. (prob. 

 7-9 mm. long), can get all the nectar, though the honey-bee (prob. 5-6 mm.) is not 

 able to do so. The entrance of the flower is a slit 67 mm. long, which is reduced 

 to about 4 mm. by the closely apposed vertical base of the lower lip. The anthers 

 are placed behind the freely open part of the slit. The style bends so far downwards 

 over these that when the proboscis of a humble-bee is inserted it must first touch the 

 stigma, and then (as in the last species) separate the filaments, causing the part which 

 has just brushed against the stigma to be dusted with pollen. Should humble-bee 

 visits fail, automatic self-pollination takes place, for in the course of anthesis the 

 entrance of the flower widens considerably, for the margins of the upper lip diverge 

 somewhat, while the lower lip bends more downwards. The style elongates pro- 

 portionately, bringing the stigma under or even between the anthers, which as they 

 wither diverge of themselves. 



Visitors. The following were recorded by the observers, and for the localities 

 stated. 



MacLeod (Pyrenees), the humble-bee Bombus mastrucatus Gerst. 5, perforating 

 the corolla-tube (Bot. Jaarb. Dodonaea, Ghent, iii, 1891, p. 314). Knuth (Schleswig- 

 Holstein), the humble-bee Bombus terrester Z., skg. legitimately: (Thuringia), 

 B. agrorum F., skg. Herm. Miiller, the same visitors as R. major : (Alps), 4 humble- 

 bees and 3 Lepidoptera. Ekstam (Swedish Highlands), a butterfly (Argynnis sp.). 

 Schulz noticed perforation by humble-bees. 



I 



