36 THE president's address. 



John Ray records that after the great fire of London, in 1666, 

 the ruins were covered with a special plant, the conditions being 

 probably favourable for its production. He calls it Erysimum 

 latifolium, smoother broad-leaved hedge mustard, and speaks of it 

 a,s growing " circa Londinum in variis locis," as " between the City 

 xind Kensington in great plenty, also about Chelsey. After the 

 great fire of London, in the years 1667 — 1668, it came up abun- 

 dantly amongst the rubbish in the ruins." The old herbalists 

 •describe it as growing in by-ways and in untoiled stony places, so 

 that in the ruins it found a congenial soil. The plant is identical 

 with Sisymh'ium Iris (Linnaeus), London Rocket. Other writers 

 liave alluded to the phenomena in a somewhat exaggerated 

 language, stating " that it had been calculated that the whole 

 •of the rest of Europe could not contain so many plants of 

 it." Statements like these have but little scientific value in 

 themselves, yet they necessarily declare a remarkable circumstance 

 that could have called forth such an utterance. The general 

 subject is a very large one, and has been well treated by many 

 able writers, from White of Selborne down to our own time. 



Whatever change takes place in the vegetable world must have 

 its complement in the animal kingdom, as there is a mutual 

 ■dependence in some form one upon the other. We may assume 

 that this takes place in minute structure, though perhaps less 

 easily discoverable even with the aid of the microscope. But 

 where such are obvious and well recorded it must add another 

 passage to the history of life. 



But, in tlis eventful history, we are every now and then being 

 a,dmonished of our ignorance by a new discovery. In the records 

 •of the British Association of the past year there was a curious 

 account of the development of the Eel, of which, as it bears a little 

 •on my subject, I may be permitted to give you an abstract. 

 Although such a familiar creature, a fish with a somewhat 

 reptilian form, it is singularly remarkable, that the story of its 

 life development has been buried in obscurity until our own time. 

 This, however, is easily understood when we know the circum- 

 stances and the extreme difficulty in arriving at the information 

 required. As a rule the salt-water fish enters our rivers to 

 spawn, but with the Eel this is reversed, as it goes to the deep sea 

 in the autumn or early winter to the depth of about two hundred 

 ^nd fifty fathoms to lay its eggs. Here it undergoes a change. 



