LABI AT AE 263 



sterile limbs of the connectives are fused for their entire length. A very complete 

 barrier to the interior of the flower is thus formed. This union of the two adjacent 

 edges of the sterile limbs is effected by papillae of varying length, and is so firm that 

 it is easier to tear the joint than to separate the two connectives. The lever 

 mechanism with its torsion-joint resembles the corresponding arrangement in 

 S. pratensis, but is simpler and firmer. 



2259. S. hispanica L., and 2260. S, tilifolia L. — Correns states that the 

 flower mechanisms of these species resemble that of S. Horminum. 



2261. S. austriaca Jacq. (Hildebrand, op. cit. ; Delpino, op. cit. ; Schulz, 

 ' Beitrage.') — Hildebrand says that in the protandrous hermaphrodite flowers of this 

 species the anther-lobes are far apart, and project from the upper lip. The upper 

 limbs of the connectives are situated on either side of this lip, and bend towards each 

 other when the connective-plate is touched in such a manner that the anther-lobes 

 come into contact in front of the entrance of the flower. Later on the stigma 

 occupies this position, owing to a curving of the style. Schulz states that purely 

 female stocks occur as well as hermaphrodite ones. 



Visitors. — Hildebrand supposes these to be moths. 



2262. S. patens Cav. — In this species also (Hildebrand, op. cit.) the anthers 

 project entirely or partly from the upper lip. The style is so placed between the 

 upper limbs of the connectives that it is obliged to share their torsion. The stigma, 

 projecting beyond the anther-lobes, must therefore first touch a visitor's back, by 

 which means cross-pollination is ensured. Ogle says that the back of an insect 

 alighting on the lower lip is at first touched in two places, i. e. by the stigma 

 dorsally, and by the anther-lobes dorso-laterally. If the insect creeps further into 

 the flower, the stigma and anthers slide along towards the tip of the abdomen, thus 

 preventing self-pollination. When a second flower is visited the stigma will come 

 into contact with one of the pollen-covered areas on the insect's body. Self- 

 pollination can be effected in flowers with styles too short for crossing. Ogle states 

 that nectar is secreted by glandular hairs situated above the lowest part of the 

 corolla-tube. 



2263. S. carduacea Benth. (Hildebrand, Ber. D. bot. Ges., Berlin, i, 1883.) — 

 The upper lip of flowers belonging to this species is not galeate, but flattened out. 

 The two filaments are very short, and their anther-lobes are respectively borne on the 

 short upper and long, widely exserted lower limbs of the connectives. Those in the 

 latter position dehisce laterally, so that insect visitors are dusted with pollen on each 

 side. In the second stage of anthesis the two stigmatic branches occupy the 

 position taken up by the anther-lobes in the first. They are therefore situated right 

 and left, and not above Dnd below as usual. 



2264. S. cleistogama De Bary et Paul. — Ascherson (Bot. Ztg., Leipzig, xxx, 

 1872) says that the plants brought to Halle from Africa bore only cleistogamous 

 flowers during the first five years, but chasmogamous ones subsequently. 



2265. S. Bertolonii Vis. — 



Visitors. — Schletterer observed the following bees at Pola. — 

 I . Anthidium manicatum L. ; 2. A. septemdentatum Ltr. ; 3. Andrena flavipes 

 Pz. ; 4. A. limbata Ev. ; 5. A. parvula K. ; 6. Bombus argillaceus Scop. ; 7. B. 



