i62 ANGIOSPERMAE—DICOTYLEDONES 



' Warnstorf describes the pollen-grains as orange-yellow in colour, ellipsoidal, 

 densely tuberculate, 37-40 ^ long and 25-7 /n broad. 



In this species (and V. Thapsus Z., V. phlomoides, L., V. pulverulentum VilL, 

 V. Lychnitis Z., V. Blattaria L., and V. blattarioides ? auct), according to Maury, the 

 anthers dehisce and touch the stigma when the flowers open. This does not, 

 however, result in fertilization, for the stigmatic papillae are not yet developed. At 

 this time, too, the conducting tissue of the style is very dense, offering great 

 resistance to the penetration of pollen-tubes, and the ovules are immature. 

 Pollination becomes effective later on, when it is effected by insect visitors, or 

 as the result of contact between the pollen-covered anthers and stigma resulting 

 from the fall of the corolla. 



Schulz observed gynomonoecism, rarely gynodioecism. 



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

 stated. — 



Herm. Miiller (Alps), 3 Muscids, a Syrphid, 3 humble-bees, a true wasp, and 

 a Lepidopterid. Knuth (on garden plants), 2 po-cltg. humble-bees (Bombus 

 agrorum F. 5, and B. terrester Z. 5) and 3 po-dvg. hover-flies — i. Eristahs 

 arbustorum Z. ; 2. Syritta pipiens Z. ; 3. Syrphus balteatus Deg. 



2046. V. Thapsus L. (Sprengel, ' Entd. Geh.,' p. 121; Herm. Miiller, 

 p. 430; MacLeod, Bot. Jaarb. Dodonaea, Ghent, v, 1893, pp. 340-1; Kirchner, 

 'Flora v. Stuttgart,' p. 576.) — The flowers of this species are only half as large as 

 those of V. thapsiforme, and of a brighter yellow. Darwin's experiments show 

 that automatic self-pollination is completely efifective. 



Visitors. — Herm. Miiller gives the following list. — 



A. Diptera. Syrphidae: all po-dvg.: i. Ascia podagrica Z'. ; 2. Helophilus 

 floreus Z. ; 3. Syritta pipiens Z. B. Hymenoptera. (a) Apidae : 4. Andrena 

 parvula K. S, apparently skg. ; 5. Apis mellifica Z. 5, po-cltg. ; 6. Bombus hortorum 

 Z. 5. do. ; 7. B. scrimshiranus K. 5, do. ; 8. Halictus cylindricus F. J, apparently 

 skg.; 9. H. smeathmanellus A''. 5, po-cltg. (h) Vespidae: 10. Polistes gallica Z. j, 

 apparently skg. (Thuringia). 



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



Knuth, po-cltg. humble-bees (Bombus agrorum F^, and po-dvg. hover-flies, 

 (Syritta pipiens Z., and Syrphus ribesii Z.). von Fricken (Westphaha and East 

 Prussia), 2 Curculionid beetles — Clonus verbasci F., and C. thapsus F. Redten- 

 bacher (Vienna), the Curculionid Clonus blattariae F. Heinsius (Holland), the 

 po-cltg. humble-bee Bombus terrester Z. ^, and the po-dvg. hover-fly Syritta 

 pipiens Z. (Bot. Jaarb. Dodonaea, Ghent, iv, 1892, pp. 57-9). 



2047. V. phlomoides L. — As long ago as the forties it was noticed by 

 Gartner that the stamens of this species degenerate (and also those of V. nigrum Z., 

 V. Blattaria Z., V. blattarioides ?auci., V. phoeniceum Z., and V. speciosum Schrad.). 

 Schulz describes the species as gynomonoecious, rarely gynodioecious ; while Comes 

 says it is self-fertile. {C/. also the remarks of Maury under V. thapsiforme.) 



2048. N. Lychnitis L. (white-flowered type). (Herm. Miiller, ' Fertilisation,' 

 p. 430, 'Weit. Beob.,' Ill, pp. 26-8; Kirchner, 'Flora v. Stuttgart,' p. 577.) — The 

 flowers of this species are homogamous and devoid of nectar. The Igwest corolla- 

 lobe is the longest, and the two upper ones the shortest, but in spite of this the 



