SCROPHULARINEAE 



207 



and as they separate more and more from one another, the superior angle {e, g, e, i ) 

 of the small part of the entrance above this will be very greatly enlarged, for the 

 sides bounding it are very short, and are forced apart as much as the long sides of 

 the lower opening. The small processes {g, i, 2) which before nearly met, and 

 which held together the two halves of the pollen-receptacle [formed by the union of 

 the four anthers] are forced apart ; the anthers, which have a tension outwards in 

 consequence of the peculiar curvature of their filaments {k, 1, 3), are freed from the 

 force that held them together below, while they remain fastened together above; 

 they therefore flap apart, and let a little pollen fall on the bee's head, exactly on the 

 spot which came in contact with the stigma scarce a second before. The pollen is 

 saved from being scattered at the sides by vertical hairs on the longer stamens 

 (i, 3) which cover the space between the upper and lower anthers on each side, 

 and project slightly beyond the lower edges. 



* Bombus hortorum L. (proboscis 20 to 21 mm.) needs to thrust its head a very 

 little way down after inserting it into the wide entrance ; but the shorter a bee's 

 proboscis is the more must it force its head down in the lower lip, and if there is not 

 space enough above the platform of the lower lip, the latter can be pressed down 

 3 to 4 mm., as far as b, z; so that bees with a proboscis only 10 mm, long may 

 reach the honey. When the bee flies away, the lower lip springs back into its 

 former position, and the whole mouth of the flower resumes its original state. 



' The flower is in this way adapted for all our native species of Bombus and 

 Anthophora, except B. terrestris and small workers of a few other species ; but the 

 length of the tube excludes all smaller bees, which if the tube were shorter might 

 carry off the honey without touching the stigma ; the hooded upper lip guards the 

 pollen from flies and other insects ; but the tube is liable to be bitten through and 

 robbed of its honey by some humble-bees, always on the left side. Such robbery 

 does little or no harm, for bees still visit in a legitimate manner flowers which have 

 been bitten through and robbed. The power of self-fertilization has been com- 

 ^^pletely lost.' 



Warnstorf describes the pollen-grains as pale-yellow in colour, tuberculate, 

 fUp to 43 /* long and 25/1* broad. 



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

 stated. 



Herm. Miiller, 7 bees i. Anthophora retusa L. 5 (proboscis 16-17 nim.), skg. 

 legitimately; 2. B. agrorum F. (prob. 12-15 mm.), do.; 3. B. hortorum Z. 5 

 )rob. 20-1 mm.), do.; 4. B. lapidarius Z. 5 (prob. 12-14 mm.), do.; 5. B. 

 :rimshiranus K. 5 (prob. 10 mm.), do.; 6. B. sylvarum Z. } (prob. 12-14 mm.), 

 10. ; 7. B. terrester Z. 5 (prob. 7-9 mm.), skg. by perforation. Knuth, 2 skg. 

 iiumble-bees Bombus lapidarius Z. 5, and B. agrorum F. Hoppner (Bremen), 

 |6 bees i. Apis mellifica Z. ^J 2. Bombus agrorum Z'. 5 ; 3. B. muscorum F. j; 

 14. B. rajellus K. ^', 5. B. terrester Z. 5; 6. Podalirius retusus Z. 5 and $. 

 [Schmiedeknecht, the humble-bee Bombus mastrucatus Gersi., one 5. Scott-Elliot 

 (Dumfriesshire), 2 humble-bees (' Flora of Dumfriesshire,' p. 133). 



2148. P. palustris L. (Herm. Miiller, ' Alpenblumen,' pp. 291-3 ; Kirchner, 

 'Flora V. Stuttgart,' p. 598; Schulz, ' Beitrage,' II, p. 218; Knuth, ' Bl. u. Insekt. 

 d. nordfr. Ins.,' pp. 1 13-14 ; Loew, 'Bliitenbiol. Floristik,' p. 399.) The rose-red 

 lowers of this species agree in the main as to their mechanism with those of 



