152 ANGIOSPERMAE—DICOTYLEDONES 



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



Knuth (North Frisian Islands), the honey-bee, 5 humble-bees (i. Bombus 

 agrorum F.; 2. B. cognatus Sleph.; 3. B. lapidarius L. ; 4. B. pratorum Z. ; 5. B. 

 terrester L.), some Anthophilids, and a butterfly (Pieris sp.), all skg. : (Rugen), the 

 bee Podalirius aestivalis Pz. 5. Friese gives 4 parasitic bees — i. Crocisa major Lep. 

 (Bordeaux, kste P^rez) ; 2. C. ramosa Lcp. (Hungary) ; 3. C. scutellaris F. (Merseburg 

 in Germany) ; 4. C. truncata Per., a 5 (Hungary). 



626. Solanutn L. 



Homogamous to protogynous pollen flowers; sometimes, perhaps, with juicy 

 basal tissue. 



2024. S. tuberosum L. (Sprengel, 'Entd. Geh.,' p. 129; Herm. Miiller, 

 'Fertilisation,' pp. 425-6 ; MacLeod, Bot. Jaarb. Dodonaea, Ghent, v, 1893, p. 339 ; 

 Kirchner, ' Flora v. Stuttgart,' p. 566; ' Bloemenbiol. Bijdragen.') — Kerner says that 

 the white or pale-violet flowers of this species droop at night, owing to bending of the 

 peduncles, and raise themselves again during the day. In the diurnal position the 



peduncle is approximately horizontal, so that the 

 plane of the corolla-limb is about vertical. Ac- 

 cording to Kerner, the flowers are open between 

 6-7 a.m., and 2-3 p.m., but some observed by me 

 remained open all day. The five yellow anthers 

 converge to form a cone projecting straight out 

 of the flower, and surrounding the style, which 

 projects beyond it, bending more or less down- 

 FiG. 282. Soiannm tuberosum, L. wards. The anthers dehisce by terminal pores, 



(from nature). Flower seen from the front. 



a, anther-pores; s, stigma. and anythmg stnkmg agamst them causes a little 



pollen to fall out. 



Owing to the position of the stigma, it is first touched by insect visitors, so that 

 cross-pollination is favoured. But, on account of the lack of nectar and scanty 

 yield of pollen, visits are few and automatic self-pollination is necessary. Kerner 

 says that this is effected by folding of the corolla, any pollen clinging to which may 

 be transferred to the stigma; while Herm. Miiller states that the downward curve of 

 the style is often strong enough to bring the stigma into the line of fall of the pollen. 



Some varieties are self- sterile (Tinzmann), other cultivated forms self-fertile 

 (Woodstock, Kidney, Grampian, and so forth). Of other kinds, some never bear 

 flowers (Ashleaf), while in others the flower-buds fall off without opening (Inter- 

 national); sometimes individual flowers open, but they and the buds fall off' 

 almost at once (Snowflake), or the flowers may open, but produce no seeds on 

 account of the absence of pollen (Early Rose, Beauty of Hebron), and this is true 

 for still other cases where abundant pollen is produced (King of Potatoes). (Justs 

 bot. Jahresber., Leipzig, viii, (1880) 1883, p. 161.) 



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

 stated. — 



Knuth (Kiel, on flowers that were mostly protogynous), the po-dvg. hover-fly 

 Syrphus balteatus Deg., and the beetle Meligethes : (Helgoland), 2 po-dvg. Muscids — 

 Coelopa frigida Fall., and Lucilia caesar L. Herm. Miiller, 2 hover-flies — Eristalis 



