SCROPHULARINEAE 185 



the bases of the stamens from a definitive distance. Pasquale, on the other hand, 

 considers that the hairy staminode with a broadened end possessed by P. gentianoides 

 Potr. is an organ for receiving the pollen which drops from the anthers, afterwards 

 effecting autogamy by transferring it to the stigma of the same flower, either by 

 spontaneous movement or with the aid of insect visitors. Such an explanation 

 could not apply to species possessing a short staminode incapable of reaching the 

 stigma. In order to explain all these relations, and also the different methods of 

 anther dehiscence and pollen dispersal, a comparative oecoldgical research on 

 numerous species is a desideratum. 



2104. P. Hartwegi Benth. In the Brussels Botanic Garden Errera observed 

 three varieties of this species, and two of 



2105. P. gentianoides Poir. He noticed that all five varieties were visited by 

 the honey-bee, humble-bees, and the hover-fly Eristalis tenax L. The bees confined 

 their attention almost entirely to the violet variety of P. gentianoides. Pasquale (op. 

 cit.), however, describes this species as almost exclusively autogamous, pollination 

 by insects scarcely ever taking place. He is of opinion that the descriptions of this 

 which have so far been given rest on inaccurate observations. 



2106. P. campanulatus Willd. (Delpino, 'Ult. oss./ I, pp. 149-50; Hilde- 

 brand, Bot. Ztg., Leipzig, xxviii, 1870; W. Ogle, Pop. Sci. Rev., London, ix, 1870, 

 p. 667 ; Herm. Muller, ' Weit. Beob.,' Ill, p. 30.) 



Visitors. The following were recorded by the observers, and for the localities 

 stated. 



Delpino, bees (sp. of Bombus, Anthidium, and Apis). Herm, Muller (in his 

 garden at Lippstadt), the humble-bee Bombus lapidarius Z. 5 and ^, skg. and 

 effecting pollination, and the bee Halictus sexnotatus K. $, skg. 



2107. P. pubescens Ait. (.?) ; 2108. P. ovatus Dougl. ; and 2109. P. con- 

 fertus Dougl. (=P. procerus Dougl). 



Visitors. Loew (Berlin Botanic Garden) observed the honey-bee, which only 

 succeeded in getting nectar in the smallest-flowered species (P. confertus), also 3 

 po-cltg. bees in the throats of the flowers i. Andrena combinata Chr.\ 2. Halictus 

 sexnotatus K.^\ 3. Osmia rufa Z. 5. 



662. Chelone L. 



Literature. Delpino, ' Ult. oss.,' I. 



Protandrous humble-bee flowers. Displacement of stamens and style and 

 secretion of nectar (on bases of upper filaments) as in Pentstemon. 



2110. C. glabra L. (Loew, ' Blutenbiol. Beitrage,' I, pp. 28-31.) This 

 species is native to North America. 



Visitors. Loew (Berlin Botanic Garden) saw the humble-bee Bombus 

 hortorum Z. $. 



663. Maurandia Or teg. 

 Style and stamens displaced as in Pentstemon. 



