18 J. M. Macfarlane. — Sarraceniaceae. 



A dipterous species found in Sarracenia according to Riley is Sarcophaga sarra- 

 ceniae which, with a beetle Euphoria (not Euryomia) melancholica , also shelters in the 

 flowers. The parent fly drops a dozen or more of her living larvae into a tube, and these 

 feed on the softer parts of captured flies. As a rule one survives at the expense of the 

 others that fall a prey to its gluttony. When mature the Caterpillar eats through the 

 tube, burrows in the ground, and in time hatehes. The writer has found S. Sledgei 

 to be badly infested by both insects, S. minor and S. flava are so to a less degree. 

 Their combined injurious attacks must have a destructive effect on the species first 

 named, and this possibly explains in part its localized distribution. 



In the New England States the only "Pitcher-plant Moth" is Exyra Rolandiana. 

 Its larvae may be noted in the old pitchers of S. pwpurea soon after the spring snows 

 have melted. They start to eat the leaf, may then move to others, and usually spin 

 a sealing web across each. Thaxter considered that the long frenulum at the base of 

 the wings gives this species its ability to crawl up the leaf. Allied to it is Papaipema 

 appassionata of the same region, which however attacks and hollows out the rhizomes. 

 It seems less unlikely to find Sarracenia pitchers utilized as breeding places for mos- 

 quitoes. J. B. Smith has shown this to be true (Entomol. News XII [19 Ol] 153, 189) 

 for Aedes fuscus and A. sapphirinus, the larvae of which may survive through Winter, 

 even though frozen in the water of the pitchers of S. purpurea. 



The pitchers of Darlingtonia always contain, according to Edwards, the living larvae 

 of a small, almost microscopic dipterous insect, whose complete historj has not been deter- 

 mined. He also observed that a small spider, probably allied to Thomiscus, spun its web 

 across the pitcher mouth, as if knowingly selecting a favorable field for its own Operations. 



Floral Structure and Pollination (Blütenverhältnisse und Bestäubungsein- 

 richtungen). With the exception of the primitive monotypic genus Heliamphora, the 

 flowers in Sarraceniaceae are solitary and each is borne on the extremity of a long 

 peduncle. In the former three to six flowers develop in racemose manner along the 

 upper part of the inclined peduncle (Fig. %). The flower buds form in August and 

 September of the previous season, but remain concealed amongst the leaf bases tili 

 Maren or April. During the former period the microspore mother-cells and the mega- 

 sporangial rudiments arise, but both rest duriog the winter in that state. The flower-stalks 

 in nearly all cases elongate, and the flowers bloom in Spring, before the leaves of the same 

 season have elongated. When the flower-stalks of Sarracenia and Darlingtonia start 

 to grow in Spring, they are straight and end in upright buds, but when the stalk is 

 fully half grown its extremity begins to bend by geotropic reaction, and within a day 

 or two the flowers have become inclined. The inverted position is retained throughout 

 the blooming period, and is a necessary one for pollination in Sarracenia. But in 

 such species as S. flava the flower-stalk gradually straightens out two to eight days after 

 pollination, so that each flower with its maturing fruit is vertical or even erect. The 

 green expanded peltate styles then form the conspieuous objeets to which the populär 

 name "watches" has been given in the Southern States. 



The bracts and sepals of Heliamphora are ovate, and are abundantly supplied wilh 

 honey glands that may differ in their cellular complexity. These glands are here 

 accessory to flower-pollination. The same type of gland therefore, and the same kind 

 of secretion, Iure insects to their destruetion over the foliage leaves, and attract them 

 in order to ensure flower-pollination over the floral leaves. 



The flower-stalk in Darlingtonia (Fig. 9) is beset by scattered linear-lanceolate 

 bracts of a pale yellow-green color. Histologically these are abundantly covered on the 

 lower, and more sparingly on the upper surface with glands. From each epidermal 

 cell on the upper surface, and in the higher bracts on the lower surface also, Springs 

 a tubercular swelling of unknown funeton. The sepals are lanceolate, of a rieher 

 yellow hue than the upper bracts, are traversed by 11 — 13 veins, have a few stomata, 

 but are devoid of or rarely show neetar glands. 



