138 



ANGIOSPERMAEDICOTYLEDONES 



two lower ones possess anthers, which are small and contain but little pollen. The 

 pollen-grains send out pollen-tubes through an opening at the upper end of each 

 anther-lobe. The capsules of the cleistogamous flowers ripen much more rapidly 

 than those of the chasmogamous ones. 



Visitors. I observed a humble-bee, a butterfly (Pieris), and Podalirius acervorum 



Z. at Kiel ; all skg. I saw a humble-bee Bombus lapidarius Z. in Sylt, skg. the 



var. flavicornis Sm., which has conspicuous dark flowers with bright orange spurs. 



Hermann Miiller observed the following in Westphalia and Thuringia. 



A. Diptera. Bombyliidae: i. Bombylius discolor Mikan,$, skg. (?); 2. B. major 



., skg. B. Hymenoptera. Apidae : 3. Bombus lapidarius Z. $, skg. ; 4. B. terrester 



ov ft 



Fig. 37. Viola calcarata, L. (after Herm. Miiller). A. Front view of flower from Piz Umbrail. 



B. Side view of the same. C. Front view of flower from Albula. D. Lower lip of the same with the 

 nectar-spur. E. Front view of the entrance of A. F. Section of A. a, anthers; c, appendages of 

 the connectives ; A 1 , pollen-collecting hairs ; A 2 , hairs which in bee-pollinated species of Viola help the bees 

 to cling to the flower : here they are useless vestiges ; k, stigma ; /, lip-like appendage below the entrance 

 (st) to the cavity of the stigma ; sd, nectar receptacle. (AD natural size ; E F X 3$.) 



L. 5, skg. (Thuringia) ; 5. Osmia bicolor Schr. 5, skg. ; 6. O. rufa Z. $, skg. C. 



Lepidoptera. Rhopalocera: 7. Anthocharis cardamines Z., skg.; 8. Pieris brassicae 



Z., skg.; 9. P. napi Z., skg.; 10. P. rapae Z., skg.; 11. Rhodocera rhamni Z., skg. 



Alfken saw the following 4 bees at Bremen : 1. Bombus arenicola Ths. 5; 2. 



B. derhamellus K. ; 3. B. muscorum F. 5 ; 4. Podalirius acervorum Z. $. 



Verhoeff observed the following in Norderney. 



A. Coleoptera. (a) Nitidulidae-. 1. Meligethes coracinus St., in perforated 

 spurs. B. Hymenoptera. (a) Apidae : 2. B. lapidarius Z. $, skg. ; 3. B. terrester 

 Z. 5, skg. ; 4. Osmia maritima Friese, one $ ; 5. Psithyrus vestalis Fourcr. 5, skg. 



C. Lepidoptera. Pieridae : 6. Pieris brassicae Z., 2 5. 



