50 OPHEEjE. CuAr. II. 



presents a wonJerful contrast in every flower producing 

 a capsule. 



Ophrys aranifera, or the Spider Ophrys. — I am in- 

 debted to Mr. Oxenden for some spikes of this rare 

 Fig. 6. species. Whilst the poUinia 



remain enclosed within their 

 cells, the lower part of the cau- 

 dicle projects up in a straight 

 line from the viscid disc, and 

 therefore has a very different 

 ^ '"a^ form from the corresponding 



Ophiys aranifera. part of the caudicle of 0. nius- 



A. PoUiniiim before the act of dfeva ; but the Upper part (A, 



B. PoUinfum^Xrthe act of fig- 6) is a little bent forward, 



depression. that is, towards the labellum. 



The point of attachment of the caudicle to the disc 

 is hidden within the bases of the anther-cells, and 

 is thus kept damp ; consequently, as soon as the 

 poUinia are exposed to the air, the usual movement of 

 depression takes place, and they sweep through an 

 angle of about ninety degrees. By this movement 

 they assume, supposip^g them to be attached to an 

 insect's head, a position exactly adapted for striking 

 the stigmatio surface, which is situated, relatively to 

 the potich-formed rostella, rather lower down in the 

 flower than in the Fly Ophrys. 



I examined fourteen flowers of the Spider Ophrys, 

 several of which were partly withered; and in none 

 were both poUinia, and in three alone was one poUinium 

 removed. Hence this species, like the !Fly Ophrys, 

 is but little visited by insects in England. In parts 

 of Italy it is even less visited, for Delpino states* 

 that in Liguria hardly one flower out of 3000 sets a 



• • Ull. OsserT. s. Dicogamia.' &c. Parte i. 1868-60, p. 1/7. 



