SCROPHULARINEAE 201 



so that all our. native humble-bees are able to do this, except Bombus terrester Z. 

 and, as Herm. Miiller adds, the small workers of some other species. Such short- 

 tongued humble-bees, and also the honey-bee, often perforate the flowers and steal 

 the nectar. The filaments adhere to the narrow part of the corolla-tube, becoming 

 free in its widened part, and then running obliquely upwards as broad stiff rods into 

 the hood-like upper lip where the anthers are situated. Their inner sides are beset 

 with short, stiff, tooth-like bristles. The anthers are laterally opposed and make up 

 together a single pollen-receptacle. The anther-lobes are produced downwards into 

 spiny appendages, by the separation of which the pollen-receptacle can be opened. 

 This is practicable because, though the anthers are stiffly united with their filaments 

 and closely apposed along their hinder and upper margins, their lower front edges 

 are only loosely connected by hairs, and therefore easily separate when subjected to 

 slight lateral impact, so that pollen falls out of the receptacle. Should the proboscis 

 of a humble-bee be inserted into the flower and touch one of the spinose anther- 

 appendages it will consequently open the receptacle and get sprinkled with the fine 

 dust-like pollen. The proboscis must be introduced into the corolla-tube exactly in 

 the middle and high up, guided by the soft hairs on the upper lip and anthers. The 

 slightest deviation from this direction would bring its delicate tip into painful contact 

 with the sharp projections on the filaments. If such penetration takes place before 

 the opening of the pollen-receptacle the stigma will be touched, so that the visits of 

 humble-bees to this species ensure crossing. The style runs along the upper edge 

 of the corolla-tube, and bends over the pollen-receptacle ; hence the stigma hangs 

 down in the uppermost part of the opening of the flower, between the soft hairs of 

 the upper lip, and will be first touched by the proboscis of a humble-bee, and cross- 

 pollinated if this has previously been dusted with pollen in another flower of the 

 same species. 



Should the visits of humble-bees fail, automatic self-pollination takes place as 

 a last resort. The end of the style bends more and more downwards, and finally 

 inwards, so that the stigma is brought under the slits of the pollen-receptacle, which 

 finally open of themselves and pollinate it autogamously. 



Lundstrom says that the bracts continue to secrete nectar and attract ants until 

 the fruits are ripe. In size, shape, colour, and weight, the seeds closely resemble the 

 pupae (so-called ' eggs ') of these insects, which remove them from their capsules and 

 carry them to their nests, where germination takes place. (Soc. Scient. Acta, Upsala, 

 Ser. 3, xiii, 1887.) 



Visitors. — Herm. Miiller (H. M.) and Buddeberg (Budd.) observed the following 

 in Westphalia and Nassau, respectively. — 



A. Diptera. Stratiomyidae: i. Oxycera pulchella Mg., vainly searching for 

 nectar, and, apparently, pollen (H. M.). B. Hymenoptera. Apidae : 2. Apis 

 mellifica Z. 5, very freq. (H. M.) ; 3. Bombus agrorum Z". 5 and 5, skg. legitimately ; 

 first carefully inserting its proboscis, and then going to another stock, thus effecting 

 crossing ; 4. B. hortorum Z. 5, do. (H. M., Siebengebirge) ; 5. B. lapidarius, 5 and ^, 

 freq., steahng nectar by perforation (H. M.) ; 6. B. pratorum Z. 5 and 5, do. (H. M., 

 Siebengebirge); 7. B. sylvarum Z. 5, skg. (H. M., Fichtelgebirge) ; 8. B. terrester 

 Z. 5, freq., behaving as 5. (Luisenburg), vainly trying to suck (Wollershof in the 

 Bavarian Oberpfalz, H. M.) ; 9. Megachile circumcincta Z'. 5, once, skg. legitimately 

 (H. M.). 



