PROCEEDINGS OF THE QUEKETT MICROSCOPICAL CLUB. 93 



l)rouglit it to Mr. Traviss's notice. Mr. Dick had a magnifying 

 ^lass, mounted in the usual way in a metal ring, which had been 

 cracked. By tightening up the ring the crack had gradually 

 healed up. Mr. Traviss exhibited a piece of glass which had been 

 ■cracked and then clamped — the crack had healed and was only 

 visible with difficulty, but Mr. Traviss said that it was not quite 

 so strong as before. A hearty vote of thanks was accorded to 

 Mr. Traviss for his interesting exhibit and remarks. 



Dr. Rendle then delivered the remainder of his Presidential 

 Address which had been held over from the previous meeting. 

 After recapitulating some of the main points of his address, the 

 President went on to describe the pollination of Orchis maculata. 

 As is well known, the pollinia of this orchid are so arranged that 

 they become attached to the head of a bee entering the flower. 

 The stalks then bend over so that when the bee enters another 

 flower the pollinia are pressed against the stigma. This is one 

 of the most perfect devices for ensuring insect pollination. In the 

 bee-orchis there is a similar arrangement ; but, although the 

 flower retains a most striking form and coloration, it has lapsed 

 into the habit of self-pollination, the pollinia merely falling from 

 the anther case on to the stigma beneath. These instances are 

 rare in the orchid family, which is a large and widespread one, 

 and although we know little about the pollination of exotic 

 orchids, we may assume that the amazing variety of form and 

 colour is associated with a correlated variety in the type of visiting 

 insect. Dr. Rendle then said that if we supposed all orchids to be 

 extinct except those that were self-pollinating, and all sundews 

 to be extinct except those that had acquired a climbing habit 

 (described in the earlier part of the address), it would be extremely 

 difficult to explain their remarkable adaptations. 



Dr. Rendle in conclusion drew attention to a remarkable 

 variation which occurs in some grasses grov.dng under Arctic 

 conditions, where they have no time to ripen their seeds. The 

 plants multiply by means of a form of vegetative reproduction 

 known as " vivipary." The flowers are transformed into green 

 shoots, the inner glumes being metamorphosed into leaves and the 

 inner portion becoming sappy, while the lower part of the axis 

 withers up, and tiny roots are ready to shoot out. These shoots 

 fall to the ground in due course and take root. Some species are 

 found — e.g. Poa alpina — in which reproduction is effected some- 



