LABIATAE 293 



Knuih, the humble-bee Bombus agrorum F., skg. Schulz, perforated flowers, 

 Herm. Muller (H. M.) and Buddeberg (Budd.), 3 bees i. Bombus agrorum F. j, 

 in large numbers, skg. (H. M.); 2. B. hortorum L. j, occasional, skg. (H. M.); 

 3. Rhophites quinquespinosus Spin. S, creeping right into the flowers to suck 

 (Budd.). Alfken (Bremen), 2 humble-bees, skg. Bombus hortorum L. 5 and J, and 

 B. ruderatus F. 5 and J. Hoppner (Bremen), 3 humble-bees i. Bombus arenicola 

 Thorns.^', 2. B. lapidarius Z. 5; 3. Podalirius retusus Z. 5. 



2325. G. Ladanum L. (Herm. Muller, 'Fertilisation,' p. 493, 'Weit. Beob.,' 

 Ill, p. 48, ' Alpenblumen,' p. 312; Schulz, 'Beitrage,' II, pp. 197, 221 ; Kirchner, 

 ' Flora V. Stuttgart,' p. 625; Knuth, 'Bloemenbiol. Bijdragen,' 'Bliitenbiol. Herbstbeob.') 

 In this species the corolla is purple-red, with a yellow spot dotted with red on the 

 lower lip, and a tube n-i6 mm. long, the wider part at the top being 5-6 mm. in 

 length. As in G. ochroleuca, the stigmatic branches project beyond the longer 

 stamens, so that the lower, downwardly directed branch is always first brushed 

 against by the back of the humble-bee visitor at the beginning of anthesis, cross- 

 pollination being thus ensured. Towards the end of anthesis the tip of this stigmatic 

 branch bends so far back that it is brought under the anthers of the longer stamens. 

 Should insect visits fail, therefore, automatic self-pollination is possible as a last 

 resort ; otherwise the flower-mechanism agrees with that of G. Tetrahit. 



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

 stated. 



Knuth, 2 humble-bees Bombus agrorum F., and B. lapidarius Z., skg. Herm. 

 Muller (H. M.) and Buddeberg (Budd.). A. Diptera. Bombyludae: i. Bombylius 

 canescens Mik., skg. (Budd.). B. Hymenoptera. Apidae : 2. Bombus agrorum 

 F. 5, skg, (H. M.) ; 3. B. lapidarius Z. J, skg. (H. M.) ; 4. B. sylvarum Z. 5, skg. 

 (H. M., Budd.) ; 5. Nomada jacobaeae Pz. $, skg, (H. M.). C, Lepidoptera. 

 Rhopalocera: 6. Pieris brassicae Z., skg. (Budd.). Schenck (Nassau), the elegant 

 bee Podalirius bimaculatus Pz., loudly humming. Hoffer (Steiermark), the humble- 

 bee Bombus argillaceus Scop. 5 and 5- Herm. Muller (Alps), 4 bees and 3 Lepido- 

 ptera. MacLeod (Pyrenees), the humble-bee Bombus hortorum Z. J, skg. legitimately 

 (Bot. Jaarb. Dodonaea, Ghent, iii, 1891, p. 332). 



Schulz found the variety angustifolia Ehrh. with female flowers (usually not 

 more than 5 % in number) distributed gynomonoeciously, rarely and sporadically 

 gynodioeciously. He, like Hermann Muller, describes the hermaphrodite flowers as 

 homogamous or sometimes feebly protandrous, varying greatly in size, and often 

 perforated. 



Schulz, in rare instances, noticed female flowers on the variety latifolia Hoffm. 

 Their distribution was gynomonoecious, rarely gynodioecious. These flowers also 

 vary greatly in size, and were found by Schulz to be homogamous or feebly 

 protandrous. 



2326. G. versicolor Curt. ( = G. speciosa Mill>^. (Axell, 'Cm Anord. for 

 Fanerog. Vaxt. Befrukt.,' p. i8; Herm, Muller, 'Fertilisation,' p. 493; Kirchner, 

 'Flora V, Stuttgart,' p. 624; Warnstorf, Verb. bot. Ver., Berlin, xxxviii, 1896 ; Knuth, 

 ' Bloemenbiol. Bijdragen.') In this species the bright yellow corolla possesses a con- 

 spicuous dark-violet nectar-guide in front ; the lower lip is yellow at the base. The 

 corolla-tube is 18-22 mm. long, and expands for 6-8 mm. above, so that a proboscis 

 of 12-16 mm. long is necessary to reach the nectar-bearing base of the flower. As 



