PROCEEDINGS OF THE SOCIETY. 471 



symmetry or segmentation of many cojlenterates, and stated that 

 a similar arrangement of organs was to be found in some primi- 

 tive flat-worms, while some of the turbellarians showed distinct 

 segmentation or repetition of corresponding organs. He expressed 

 the opinion that segmentation was not likely to arise de novo in 

 highly-differentiated forms, and that the main line of descent of 

 the vertebrates was everywhere composed of segmented animals. 

 He mentioned that the ascidians, which he had elsewhere shown 

 did not exhibit segmentation, were probably not in this direct 

 line. After reviewing the " Annelid Theory," the lecturer con- 

 cluded by pointing out that the repetition of similar parts in 

 animals furnished a wealth of material which nature had utilised 

 in the production of the complex structure of the higher verte- 

 brates. A cordial vote of thanks was given to Dr. Rankin for his 

 lecture. Members of kindred societies and friends of members had 

 been invited to the meeting, and there was a large attendance. 



28th March, 1899. 



Mr. Robert Kidston, F.R.S.E., F.G.S., President, in the chair. 



Miss M. A. M. Kidston, 24 Victoria Place, Stirling, and Mr. 

 Alexander Patience, 2 Golfhill Terrace, Dennistoun, were elected 

 as Ordinary Members. 



Mr. James F. Gemmill, M.A., M.B., CM., showed a mounted 

 specimen of the bones of the pelvis and right leg of a Wood- 

 pigeon, the left leg having been entirely awanting. The case 

 was remarkable, on account of the well-developed condition of the 

 left half of the pelvis, and the presence there of an almost 

 normal acetabular cavity. Dr. Gemmill also showed about 

 twenty malformed young trout, obtained from the hatcheries at 

 Lochwinnoch. Most of the specimens were of the double-monster 

 type, and they formed a series of stages ranging from complete 

 separation of the embryos in the yolk sac to cases in which the 

 two embryos were quite fused together except at the fore part of 

 the head. The large median eye present in some of the latter 

 was specially striking. 



Mr. John Lindsay, M.A., M.B., CM,, showed a specimen of 

 the peculiar variety of Gold-fish cultivated by the Chinese, in 

 which the dorsal fins and tail are double. 



