346 Royal Society of Edinburgh. 



there will be opened up a new sphere of geological inquiry of the 

 highest order. With the aid of a transelemental chemistry (for we 

 understand Dr. Brown has transformed several other elementary forms 

 besides carbon) we may approach the subject of the molecular ge- 

 nesis of the earth ; and the geological relations of carbon and silicon 

 are certainly sufficiently striking to warrant the entertainment of 

 this hope. As it is, there are several points in natural history which 

 seem to be illustrated by the particular case of transformation now in 

 hand. As one instance, we would specify the siliceous character of 

 many organic remains found in circumstances in which the source of 

 silicon is perplexing and unintelligible. 



In the discussion which followed. Professor Traill remarked, that 

 though he had not had an opportunity of repeating Dr. Brown's ex- 

 periments, yet, from his acquaintance with that gentleman, he had a 

 strong conviction of their value ; and this notwithstanding the very 

 startling principles and extraordinary conclusions to which they ne- 

 cessarily led. He had no hesitation in saying, that since the early 

 days of Davy, when that great chemist brought the metalloids to 

 light, no investigation had been made approximating in importance 

 to the present, whose publication would do honour to the Society, 

 and whose interest, as it regarded the subjects of Botany, Palaeonto- 

 logy and Geology, in its widest range, was altogether unbounded. 



Professor Christison begged to meet a statement which he under- 

 stood had gone abroad, that he had given a guarantee to the accu- 

 racy of these investigations. This was by no means the case. The 

 fact was, that, now for some time otherwise employed, he was 

 not capable even of testing these admirable experiments : no one, in 

 fact, could do so but a first-rate analytic chemist, perfectly master of 

 the most recent manipulations of the laboratory ; and he would warn 

 every one against coming to a decision regarding these conclusions, 

 well styled startling, either for or against, without such preliminary 

 investigation. At the same time, it was true that he had been fa- 

 miliar with the details of the inquiry ; he had searched, along with 

 the author, but in vain, for grounds of fallacy, and he formed the very 

 highest estimate of their value and importance. 



Professor Syme communicated a paper by Mr. Goodsir, " On the 

 Anatomy of Amphioxus lanceolatus of Yarrell." 



After a short statement of the labours of Yarrell, Couch, Retzius 

 and Miiller, the author gave a detailed description of the structure 

 of Amphioxus, as observed in the dissection of one of two specimens 

 taken by Mr. Forbes in the Irish Sea. The abdominal folds, and the 

 anterior and posterior anal fins were described, and the existence of 

 a fin in front of the anus illustrated by an observation made by Pro- 

 fessor Agassiz, of the temporary existence of a similar fin in the em- 

 bryos of certain freshwater fishes. 



The osseous system presented two divisions, — the true or neuro- 

 skeleton, and the intestinal or splanchno- skeleton. The true skeleton 

 consisted of a chorda dorsalis, equally pointed at both extremities, 

 without the slightest trace of a cranium, and destitute of any of the 

 peripheral vertebral elements, with the exception of a row of cells — 



