46 



sufficient irritation to account for the pneunaonic symptoms. 

 These observations were interesting as showing that the much 

 criticised views of Klein, Tegetmeier, and others on " pneumo- 

 enteritis " as a cause of mortality in Grouse may have some 

 foundation in fact. 



Dr. J. F. Gemmill, M.A., D.Sc, Lecturer on Embryology in the 

 University of Glasgow, gave an account, illustrated by lantern- 

 slides and specimens, of his memoir on " The Development of 

 Solaster encleca Forbes," communicated to the Society by Prof. 

 J. Arthur Thomson, F.Z.S. 



The author described the ovaries and ova and the processes 

 of spawning, fertilization, segmenta,tion, and gastrulation, and then 

 dealt with the characters of the free-swimming larvse and the 

 changes related to the metamorphosis. He discussed the develop- 

 ment of the internal cavities and of the skeleton, and described 

 the methods he had employed in obtaining and rearing the larvae. 



The memoir, in addition to details of adult anatomy, contained 

 a description of the following points in development : — 



Segmentation total equal ; blastula by egression ; gastrula by 

 invagination ; early closure of blastopore ; no larval mouth. 



Free-swimming larva with three arms and a muscular sucker ; 

 attachment by sucker. 



Metamorphosis such that while in point of external form the 

 left side of the larva becomes the oral surface of the starfish, in 

 reality the epiderm of the oral surface is derived in great part fi'om 

 that of the anterior part of the early bilateral larva, and conversely 

 the aboral epiderm is derived chiefly from that of the posterior end 

 of the larva. 



Archenteron dividing into anterior and posterior vesicles and 

 middle chamber or enteron. Anterior vesicle giving rise to pre- 

 oral, axial, and epigastric cceloms, hydroccele, dorsal sac, internal 

 oral sinus, and part of external oral sinus. Posterior vesicle 

 giving rise to hypogastric and pharyngeal coeloms, rest of external 

 oral sinus, aboral circular sinus, and genital rachis. 



The full set of hydroccele pouches completed slowly, the series 

 running in the watch-hand direction as seen from the oral side ; 

 opening of stone-canal between radii I and II ; anus in inter- 

 radius V/YI. 



Terminal plates double ; rest of aboral plates showing atypical 

 distribution. 



A larval nervous system and a statolith -like body in the 

 posterior ccelom. 





Mr. F. E. Beddard, M.A., F.K.S., F.Z.S., Prosector to the 

 Society, presented a paper " On the Alimentary Tract of certain 

 Birds, and on the Mesenteric Relations of the Intestinal Loops," 

 based on notes he had accumulated relative to the viscera of 

 Birds which had died in the Society's Gardens. The paper dealt 



