UMBELLIFERAE 469 



crowded together into conspicuous dark-blue capitate umbels. These are surrounded 

 by a spinose involucre, which makes it almost impossible for soft-skinned animals like 

 snails or caterpillars to creep up from below, and enter the umbel as unbidden guests. 

 The involucre is supplemented by trifurcate bracteoles, situated at the base of each 

 flower, and also by the five sharply pointed sepals. 



The filaments are incurved in the bud, so that the anthers are enclosed in the 

 corolla, which is about 4 mm. long. At this time the bluish colour of the foliage- 

 leaves is not yet well marked, but the whole plant is whitish, and therefore not so 

 conspicuous as later on, when the filaments have elongated and the flowers have 

 entered upon their first (male) stage. 



Meanwhile, the 10-rayed disk has begun to secrete. The petals are incurved at 

 the tip, and closely apposed, only leaving a space for the passage of the filaments. 

 This firm approximation of the parts of the flower, and the deep situation of the 

 nectar, makes sucking impossible for any but strong insects with a proboscis at least 

 3-4 mm. long ; and in consequence of this large or middle-sized insects are almost 

 the only visitors observed. These get dusted with pollen from the anthers, which 

 project about 3 mm. beyond the corolla, and when visiting other flowers in the 

 second stage necessarily pollinate the stigmas, which in such flowers are at a 

 corresponding level. In the second stage of anthesis the anthers have dropped 

 off, and the long stigmatic branches project a long way out of the flower. Self- 

 pollination is therefore prevented. 



Visitors. I observed the following, all skg., on the shores of Kiel Bay, 

 and in Sylt. 



A. Diptera. 1. Syrphus ribesiiZ. ; 2. S. umbellatarum F. B. Hymenoptera. 

 3. Apis mellifica L. ; 4. Bombus lapidarius L. C. Lepidoptera. 5. Lycaena 

 semiargus Rott.\ 6. Polyommatus phlaeas Z. ; 7. Vanessa atalanta Z.; 8. V. 

 urticae L. 



MacLeod observed Apis and other bees, Vespa, and hover-flies, in Belgium. 



Loew noticed the following in Mecklenburg (' Beitrage,' p. 41). 



A. Diptera. Muscidae : 1. Sarcophaga carnaria Z. B. Hymenoptera. 



(a) Apidae: 2. Bombus distinguendus Mor. 5, 5, and J, skg., *j> and 5, also po-cltg. ; 

 3. B. soroensis F. 5, skg. (b) Sphegidae: 4. Ammophila sabulosa Z., skg.; 

 5. Cerceris arenaria Z. <5, do. 



1097. E. campestre L. (Herm. Miiller, 'Fertilisation,' pp. 271-2; Kerner, 

 ' Nat. Hist. PI/ Eng. Ed. 1, II, pp. 278, 311, 323 ; Schulz, ' Beitrage,' I, p. 42 ; Knuth, 

 ' Bloemenbiol. Bijdragen.')' Hermann Miiller describes the flower mechanism of this 

 andromonoecious species as closely resembling that of E. maritimum. The her- 

 maphrodite flowers are protandrous. The nectary here again is a depression 

 surrounded by a ten-lobed ridge, and secreting abundant nectar. This is completely 

 concealed at some depth, for the nectary is surrounded by the five stiff erect petals, 

 which are about 3 mm. long, and sharply incurved at their tips. Outside all are the 

 five rigid awn-like sepals, acuminate in shape and projecting considerably beyond the 

 petals. The sepals, together with the equally stiff and spinose involucral bracts, form 

 an effective protection against unbidden guests. As first pointed out by Schulz, the 

 styles project early from the flower, so that, as in the last species, there is apparent 

 protogyny. It is probably for this reason that Kerner actually describes Eryngium as 



