HYPERICINEAE 205 



510. H. quadrangulum L. (Herm. Mailer, ' Fertilisation,' p. 141, ' Weit. Beob.,' 

 II, p. 212; MacLeod, Bot. Jaarb. Dodonaea, Ghent, vi, 1894, p. 266; Kirchner, 

 'Flora V. Stuttgart,' p. 325; Knuth, ' Bliitenbiol. Beob. a. d. Ins. Riigen,' ' Bloemen- 

 biol. Bijdragen.') — Hermann Miiller says that this species is intermediate between 

 the two foregoing ones in respect of the size of the flowers and the number of 

 stamens. He observed that in open flowers the stigmas were not in immediate 

 contact with the anthers. Probably, however, when fading takes place, there is 

 a contraction of parts followed by automatic self-pollination. 



Visitors. — Herm. Miiller (H. M.) and myself (Kn.) have observed the 

 following. — 



A. Diptera. {a) Muscidae: i. Aricia vagans Fall., po-dvg. (H. M.). (p) 

 Syrphidae : 2. Syritta pipiens L., po-dvg. (Kn.) ; 3. Syrphus balteatus Deg., do. 

 (H. M.) ; 4. S. ribesii Z., do. (Kn.). B. Hymenoptera. Apidae : 5. Apis mellifica 

 L. 5, po-cltg. (Kn.); 6. Bombus agrorum i^ 5, do. (Kn., Riigen); 7. B. terrester 

 Z. 5, do. (Kn.). The latter humble-bee was also observed by Loew in the Berlin 

 Botanic Garden, po-cltg. 



In Dumfriesshire, Apis, 3 humble-bees, a Dolichopid, and 3 Muscids have been 

 recorded (Scott-Elliot, 'Flora of Dumfriesshire,' p. 32). 



511. H. commutatum Nolte (=H. perforatum x H. quadrangulum). 

 Visitors. — Loew observed Apis mellifica Z. 5 and Bombus terrester Z. 5, both 



po-cltg., in the Berlin Botanic Garden. 



512. H. tetrapterum Fries. (Herm. Miiller, ' Weit. Beob.,' 11, p. 212 ; Kirchner, 

 'Flora v. Stuttgart,' p. 325.) — In this species again the flower mechanism is similar to 

 those of allied forms. Kirchner states that automatic self-pollination is usually 

 impossible in the open flower. 



Visitors. — Herm. Miiller gives the following. — 



A. Coleoptera. NitiduUdae: i. Meligethes aeneus /"., po-dvg. B. Diptera. 

 {a) Muscidae : 2. Aricia incana Wiedem., freq., po-dvg. ; 3. A. vagans Fall., do. 

 {b) Syrphidae: 4. Syrphus balteatus Deg., po-dvg. C. Hymenoptera. Apidae: 

 5. Apis mellifica Z. 5, po-cltg. ; 6. Bombus terrester Z. $ and 5, do. 



MacLeod observed a humble-bee and a Muscid in Flanders (Bot. Jaarb. 

 Dodonaea, Ghent, vi, 1894, p. 226). 



513. H. pulchrum L. (Knuth, ' Bl. u. Insekt. a. d. nordfr. Ins.,' p. 49.) — The 

 flower mechanism once more agrees with those of related species. The diameter of 

 the flowers of plants studied by me in the North Frisian Islands is about 1-5 cm.; 

 the number of stamens is about fifty. 



Visitors. — MacLeod observed small Diptera in Flanders (Bot. Jaarb. Dodonaea, 

 Ghent, vi, 1894, p. 378). 



In Dumfriesshire, Apis and numerous Diptera were recorded (Scott-Elliot, 

 ' Flora of Dumfriesshire,' p. 53). 



514. H. humifusum L. (Herm. MuUer, 'Fertilisation,' p. 141 ; MacLeod, Bot. 

 Jaarb. Dodonaea, Ghent, vi, 1894, P- 226; Kirchner, 'Flora v. Stuttgart,' p. 326; 

 Knuth, ' Bl. u. Insekt. a. d. nordfr. Ins.,' p. 52.) — The flowers of this species observed 

 by me in the North Frisian Islands had only 10-15 stamens. Automatic self- 

 pollination regularly takes place in closing flowers, and often also even in open 

 ones (Herm. Miiller). Kerner says that the flowers do not open in unfavourable 



