PROCEEDINGS OF SCIENTIFIC SOCIETIES. 27 



Mr. J. Harris Stotie exhibited specimens of the dried plant, and made 

 remarks on Lychnis viscaria as a trap for ants. He pointed out that three 

 or four glutinous, sticky rings are situate immediately underneath the 

 nodes in the flowering stalks. Ants climbing are arrested and die in 

 numbers at the sticky zones. In Norway he had observed 95 per cent, of 

 the plants with dead ants thereon ; and he submits (1) whether the zones 

 are a protection to the flowers, (2) the ants noxious, or (3) their dead bodies 

 serve as nutriment to the plant? 



Dr. Cobbold exhibited diseased roots of Stephanotus, which he had 

 received from Dr. Masters. They swarmed with myriads of nematode 

 worms, and were also covered with minute Acari. He referred the worms 

 to the genus Leptodera, and stated that thirty years back he discovered 

 similar parasites on the shrivelled leaves of Gloxinias. 



Prof. Owen read a paper " On the Homology of the Conario-hypo- 

 physical Tract; or the so-called Pineal and Pituitary Glands." He 

 propounds the view that it is the modified homologue of the mouth and 

 gullet of Invertebrates ; that the subcesophageal ganglia or ganglionic 

 masses, or neural cords, constitute the centres whence are derived and 

 caudally continued the homologues of the vertebrate spinal cord. 



The President, Sir John Lubbock, then read a paper " On the Sense of 

 Colour among the Lower Animals," containing an account of some experi- 

 ments made on a species of Daphnia, a small fresh-water crustacean, in 

 order to determine its power of distinguishing colour and the limit of its 

 power of vision. If a beam of light is passed through a prism and thrown 

 on a white surface, we get, as everyone knows, a spectrum consisting of the 

 colours of the rainbow, beginning at one end with red and ending with 

 violet. But though the red and the violet are the limit of our powers of 

 vision, it is hardly necessary to say that the rays of light extend farther in 

 both directions ; that is, beyond the red at one end and the violet at the 

 other. It is an interesting problem, then, whether the limits of vision of 

 other animals are the same as ours, or whether they are able to perceive 

 any of the rays which are invisible to us. M. Paul Bert, some years ago, 

 made experiments with Daphnias, and came to the conclusion that their 

 limits of vision are the same as ours. Nay, he even felt justified in 

 extending their generalisation to all animals. Sir John Lubbock, however, 

 has already shown that ants do possess the power of perceiving the ultra- 

 violet rays. His present experiments were made on Daphnias. He pointed 

 out that if his conclusions differed from those of M. Paul Bert, it was 

 probably because — thanks to Prof. Dewar and the authorities of the Royal 

 Institution — he was able to experiment with more perfect appliances. He 

 considers that Daphnias have certainly the power of perceiving the ultra- 

 violet rays considerably beyond the limit visible to our eyes. This fact 

 opens up various physiological questions of much interest, as for instance, 



