6l2 



ANCIOSPERMAE—DICOTYLEDONES 



turning their stigmatic surfaces upwards, and protrude a little from the bell, while the 

 empty anthers become somewhat retracted. The disk-florets are usually surrounded 

 by 5 ray-florets with large corolla-limbs and no stamens ; these increase the diameter 

 of the head to 9-10 mm. 



Failing insect-visits, automatic self-pollination is effected in the disk-florets by 

 the fall of pollen from the sweeping-hairs on the outspread stigmatic papillae. 



Gynodioecism is also said to occur occasionally. 



Fig. 199. Achillea MilU/olium, L. (after Herin. Miiller). (i) A single head, seen from above: 

 ■a, stigmas of purely female ray-florets; b, do. of disk-florets in the second stage; c, anther-cylinder of 

 disk.floret in the first stage; d, bud nearly ready to open. (2) Single disk-floret in the act of opening, 



^een in longitudinal section: e, ovary; yj nectary; g, style; A, corolla-tube; «, filaments; k^ stylar 

 branches; /, tip of the style, with sweeping-hairs; w*, anther-cyiinder ; w, throat of corolla; o, valves 

 ■closing the anther-cylinder. (3) Disk-floret (with bract) somewhat more advanced ; pollen is issuing 

 from the anther-cylinder. (4) Older disk-floret ; the diverging stylar branches protrude, and the 



anther-cylinder is retracted into the corolla. (5) Tip of the style of a disk -floret in the first (male) stage : 

 k\ stigmatic papillae ; /, sweeping-hairs ; ^, pollen-grains. 



Chrysanthemum Leiicauthcmu-m, L. (6) Disk -floret in the first (male) stage : p, pollen. (7) Do., 

 in the second (female) stage. (8) Tip of a stylar branch, seen from within (X 60): k\ stigmatic 



papillae ; /, sweeping-hairs. 



Visitors. — I observed the following in Schleswig-Holstein (S.-H.), and on the 

 higher part of Helgoland (H.). — 



A. Coleoptera. All po-dvg. {a) Curculionidae: i. Apion marchicum Hbst. 

 (S.-H.). (fi) Nitidulidae: 2. Meligethes sp. (S.-H.). (<:) Tehphoridae: 3. Cantharis 

 fulva Scop. (S.-H.). B. Diptera. {a) Muscidae : all skg. : 4. Anthomyia sp. (S.-H.) ; 

 5. Aricia incana Wted. 5 (S.-H.) ; 6. Dolichopus plumipes Scop. (S.-H.) ; 7. Leucostoma 

 aenescens Zeii. (S.-H.) ; 8. Lucilia caesar Z. (S.-H.) ; 9. Musca corvina J^. (S.-H.) ; 

 10. Nemotelus uliginosus Z. (S.-H.); 11. Oliviera lateralis J^., skg. (S.-H.); 

 12. Onesia sp. (S.-H.); 13. Pollenia sp. (S.-H.); 14. Sarcophaga carnaria Z. 

 (S.-H.); i."^. S. striata Fair. (S.-H.); 16. Scatophaga lutaria I". (S.-H.); 17. S. 

 merdaria F. (S.-H.); 18. S. stercoraria Z. (S.-H. and H.); 19. Spilogaster carbo- 



