544 



ANGIOSPERMAE—DICOTYLEDONES 



MacLeod (Pyrenees) observed a variety of this species (possibly G. Lapeyrou- 

 sianum) to be visited by a beetle, 3 Muscids, and 3 Syrphids. He describes it as 

 belonging to flovifer class C, while the other species of Galium belong to E. 



1247. G. verum L.xG. Mollugo L. ( = G. ochroleucum Wolf.). (Knuth, 

 ' Weit. Beob. u. Bl. u. Insekt. a. d. nordfr. Ins.,' p. 235.) — In the island of Sylt 

 (2. 7. '93) I have seen numerous insects visiting in succession the flowers of 

 G. verum Z. and G. Mollugo L., and bringing about an interchange of pollen. 

 G. ochroleucum Wolf., which grows along with these two species, proves that this 

 crossing is effective, for it is a hybrid between them. 



Visitors. — I observed the following Diptera, skg. — 



I. Coenosia tigrina F.; 2. Dolichopus aeneus Deg.; 3. Hylemyia sp. 5. 

 4. H. variata F. ; 5. Spilogaster communis R.-D. ; 6. S. duplaris Zett. ; 7. S. 

 duplicata 77/^. ; 8. Stomoxys stimulans i1/f . 5. 



1248. G. verum L. (Herm. Miiller, 'Fertilisation,' p. 301, 'Weit. Beob.' Ill, 

 p. 70; MacLeod, Bot. Jaarb. Dodonaea, Ghent, v, 1893, p. 387; Knuth, 'Bl. u. 



Insekt. a. d. nordfr. Ins.,' pp. 82-3, ' Blu- 

 tenbiol. Beob. a. d. Ins. Riigen,' ' Weit. 

 Beob. ii. Bl. u. Insekt. a. d. nordfr. Ins.,' 

 p. 235; Schulz, 'Beitrage,' I, p. 67.) — 

 The plants of this species that I examined 

 in the island of Rom possessed the fol- 

 lowing flower mechanism. — The buds are 

 odourless, but when the corolla expands 

 a very strong smell of cumarin is exhaled. 

 (Kerner compares it to that of honey.) 

 The flowers are only 4 mm. in diameter, 

 but being crowded into dense inflorescences 

 their intense yellow colour makes them 

 conspicuous from a distance. They are 

 markedly protandrous. In the first stage 

 of anthesis the four stamens bend back so 

 far that the lower parts of their filaments 

 lie between the lobes of the flat expanded 

 corolla. At the same time the upper 

 parts of the filaments are curved upwards, so that the dehisced anthers are in the 

 way of chance visitors. After these have completely or partly shed their pollen, 

 the two styles, so far united, separate, grow a little, and raise the mature stigmas 

 almost to the level occupied by the anthers during the first stage of anthesis. 



Autogamy occasionally results from the bending over of the filaments, till the 

 anthers touch the stigmas. Automatic geitonogamy is frequently brought about by the 

 fall of pollen from a higher flower on to the stigmas of a lower one. Lastly, the 

 inflorescences are so crowded, and different stocks grow so close together, that 

 xenogamy may possibly be effected by the wind. Hermann Miiller describes 

 a remarkable difference in the size of flowers from different plants, and indicates 

 this in his illustration. {^Cf. Fig. 183.) I have not noticed this in Rom, nor 



Fig. 1R2. Galium sylvestrc, Pollich {after 

 Herm. Miiller). A. Younjr flower (x 7). B. 

 Pistil and nectary of the same {.< 16). C. Older 

 flower (X 7). D. Pistil and nectary of the same 

 (X l6). «, nectary; ov^ ovary ; j/, stigma. 



