41 



• 

 become fixed to the legs and hairs of insects in a different way, viz., by means of a horny 

 hook with a slit. The object is, however, evidently the same, to bring about crossing by 

 the agency of insects. 



tribe epidendreae — (Microstylis, Liparis, Calypso, Aplectrum, Corallorhiza, Tipularia.) 



The anther in this tribe is covered by a lid which falls away or opens at maturity so 

 as to expose more or less to view four pollinia, arranged in pairs in each cell. The lid of 

 the Spring Coral-root, Corallorhiza innata, must fall very soon after the expansion of the 

 flower, for I could never find it except in buds. The stigmatic surface is turned down- 

 ward, so that it does not seem possible for the pollen to reach it spontaneously. I have 

 only once found a pollinium on a stigma of a Tway-blade, Liparis Loeselii ; but capsules 

 are generally formed in great number. 



As far as I can ascertain, no insect visitor of the flowers of this tribe is yet known. 

 Only surmises can, therefore, be made from the shape or size of the flowers. The Adder's 

 Mouths {Microstylis) must require very small insects to effect the pollination of their 

 minute flowers, while only a large bee standing on the sack-like lip of the Calypso borealis 

 could touch with its back the anther above, and extract the pollinia for the benefit of the 

 next flowers visited, 



The rare Crane-fly Orchis, Tipularia discolor, presents two characters exceptional in 

 this tribe, a spur to its lip, and its pollinia connected by a stipes or stalk to a viscous gland 

 on the rostellum. 



The shortness of the remarks on these plants, will, it is to be hoped, be an incentive 

 to attentive walkers in the woods and meadows, to ask each of their flowers some of its 

 secrets, whenever there is the opportunity. What visitors does it receive ? What 

 attraction does it offer 1 How do the guests behave ? 



tribe neottieae. — (Listera, Spiranthes, Goodyera, Epipactis, Arethusa, Calopogon 



Pogonia.) 



The great distinctive character of this tribe from the Epidendreae is the less cohering 

 pollen, which is granular or powdery, and not waxy. 



In some, Listera, Spiranthes, Goodyera, and Epipactis, the anther-lid opens in the 

 bud, and the protruding ends of the pollinia become then fixed to the rostellum ; after- 

 wards, when the flower has opened, the least contact even of a human hair, causes the 

 surface membrane of the rostellum to rupture or explode, a portion of the rostellum ad- 

 hering immediately by its viscidity to the foreign object, which on removal draws the 

 pollinia out of their cells. In the European Ladies'-tresses, Spiranthes autumnalis, and 

 Rattlesnake Plantain, Goodyera repens, the viscid strip thus carried away from the beak- 

 like rostellum, is boat-shaped, and leaves the two sides of the beak sticking up like a fork. 

 The flowers are proterandrous, that is, they ripen the pollen before the stigma ; at least, 

 when the pollinia are in a condition to be removed, the column is so bent down against 

 the lip which secretes nectar at its base, that a pollinium cannot be brought against the 

 stigma, though a bee should come loaded with one or more. In older flowers, the column 

 is found turned upwards, and pollination of the stigma can then take place. Darwin saw 

 kurnble-bees fertilise Spiranthes, alighting on the bottom of the spike, and crawling 

 spirally up it, suck one flower after another. The same insects have been observed in 

 Scotland and on the Alps, at work on the flowers of Goodyera repens, a species which 

 also occurs in Canada, as well as two more, G. pubescens and G. Menziesii. Mr. J. 

 Fletcher has in his herbarium a specimen of G. pubescens, with the head of a dipterous 

 fly sticking to the rostellum of one of the flowers ; the insect, too feeble to remove the 

 pollinia, had perished miserably. Many similar instances have beeu observed on other 

 species. Darwin mentions one on Epipactis latifolia, which belongs to the same tribe. 

 It is not unusual to find dead ants and flies on the inflorescence of the milk-weeds, hanging 

 tj-y one leg on the horny hooks of the pollinia. Even large Lepidoptera may be unable to free 

 their proboscides eemented to the pollen of the little flowers of Apocynum androsaemi- 

 folium. I found last summer a dead Ctenucha Viryinica, which had been thus caught. 



