OPHRYDE^— GYMNADENIIN^— GYMN ADEN I A 143 



was remarkably uniform in appearance and colour, the variations recorded above 

 being only the natural result of differences in the age and vigour of the plants. There 

 were no hybrids, and no intermediate forms between it and the type, which was 

 abundant a short distance away. 



Var. borealis Dr. Plant about 15 cm. high, leaves about 5 mm. broad, spur 

 thick, about as long as ovary, flowers very sweet-scented, dark purple, 3 mm. long 

 by 2-5 mm. broad, middle lobe relatively larger than the lateral. Upland pastures 

 near Watendlath, Cumberland, 1907. 



I have not seen this plant, but the description resembles in some respects the 

 Anglesey form of the sub-species densiflora. 



Gjmnadenia compsea x albida, vide G. alhida. 



Fertilisation. The viscid gland is as long as the caudicle, which stands erect at 

 its forward end. The under-surfaces of the two glands form part of the roof of the 

 mouth of the spur, so that when the moth bows its proboscis to fit the arched spur, 

 it is bound to come in contact with them. At the broad end of each viscid gland there 

 is a deep depression bordered by a slight ridge. The foot of the caudicle is attached 

 to the steep sides of this ridge and depression. On exposure to the air the ridge 

 sinks down flat, taking with it the pollinium, till the latter lies parallel with the 

 viscidium. The action is hygrometric, for if the gland is placed in water, the ridge 

 rises together with the pollinium, and when re-exposed to the air sinks down again. 

 The two stigmas are separate; each situated on an oval wing or lobe of the column, 

 and ghstening with adhesive matter, often covered with packets of pollen. The 

 elastic threads binding the latter to the polHnia are unusually weak, to avoid the 

 possibility of the whole pollinium being dragged off by the stigma through the viscid 

 material not setting hard and dry as quickly as in Orchis. If a fine bristle be inserted 

 into the spur, the long narrow viscidia will adhere to it, slightly on one side, and 

 the pollinia will then move down till they are parallel with it. If the bristle be now 

 inserted into the spur of another flower, the ends of the pollinia will touch the stigmas, 

 and leave packets of pollen adhering to them. 



Darwin wrote i^ "My son George went at night to a bank where this species grows 

 plentifully, and soon caught T'lusia chrysitis with six poUinia, P. gamma with three, 

 Anaitis plagiata with five, and Triphana pronuha with seven pollinia attached to their 

 proboscides. I may add that he also caught the first named moth in my flower-garden, 

 with the pollinia of this Orchis attached to its proboscis, but with all the pollen- 

 grains removed, although the garden is a quarter of a mile distant from any spot 

 where the plant grows. Many of the above moths had only a single pollinium 

 attached, somewhat laterally to their proboscides; and this would happen in every 



' Fert. Orch. ed. 2, p. 67. 



