Robertson — Flowers and Insects. 167 



stamens, the anthers of the outer ten discharging their pollen 

 before the others. The pistillate flowers have the stamens 

 aborted. Kerner (19) mentions S. arunciis as typical of a 

 group, in which some plants bear only perfect flowers, others 

 are andro-monoecius, a third set bear only staminate and a 

 fourth only pistillate flowers. Kerner calls the pistillate and 

 staminate flowers pseudo-hermaphrodite, but they are so very 

 different that they give a diff"erent aspect to the plants that 

 bear them, enabling one to distinguish the plants at a consid- 

 erable distance. 



The plants bearing staminate flowers are more conspicuous 

 from the simple fact that the numerous stamens are more 

 conspicuous than the pistils of the fertile flowers. On this 

 account, as well as from the fact that they yield both nectar 

 and pollen, these plants are more abundantly visited by in- 

 sects. The pistillate flowers are consequently more likely to 

 receive the visits of insects coming from the staminate flowers. 



Delpino regards /S. aruncus as adapted to the smaller bees 

 (micromelittofile piu segnalate), or at least principally visited 

 by them. Miiller found beetles more abundant, at any rate 

 in number of species, while I have taken a larger proportion 

 of beetles on it than on any other flower. 



The blooming time previously recorded (22) is extended 

 from May 24 to June 24. The following list of insects, taken 

 on the flowers on June 4, 7-10 and 20, includes the one given 

 before, with additions and corrections : — 



Coleoptera — Dermestidae : (1) Anthrenus musaeorum L.,ab.; (2) Cryp- 

 torhopalum haemorrhoidale Lee; (3) C. triste Lee, ab.; (4) Orphilus glab- 

 ratuSjF., ab.; Nitidulidae : (5) Epuraea truncateilaMann; (6) E. labilis Er. ; 

 Elateridae: (7) Sericosomus silaceus Say; 3Ialachidae: (8) Anthocomus 

 erichsoni Lee; (9) Attalus scincetus Say; Ptinidae: (10) sp., freq.; Scara- 

 baeidae: (11) Trichius piger F. ; (12) Valgus canaliculatus F.; Cerambycidae: 

 (13) Euderces picipes F., ab.; (14) Acmaeops directa Newm.; (15) Typo- 

 cerus badius Newm.; (IC) T. lugubris Say; (17) Leptura exigua Newm.; 

 (18) L. vittata Germ.; (19) L. pubera Say; Chrysomelidae: (20) Disonycha 

 limbicollis Lee. var pallipes Cr.; Bruchidae: (21) Bruchus hibisci Oliv.; 

 Oedemeridae: (22) Asclera puncticollis Say; Mordellidae: (23) Pentaria 

 trifasciata Melsh., freq.; (24) Mordella marginata Melsh., ab.; (25) Mor- 

 delUstena biplagiata Hel., freq.; (26) M. ornata Melsh.; (27) M. aspersa 

 Melsh., freq.; (28) M. tosta Lee. ; (29) M. pubescensF. ; Curculionidae; (ZO) 

 Centrinus picumnus Hbst., ab. — all s. or f. p. 



Hymenoptera — Apidae (31) Heriades carinatum Cr. (^, s.: (32) Nomada 



