No. 104. 



ABSTRACT OF THE PROCEEDINGS 



OF TUE 



ZOOLOGICAL SOCIETY OF LONDON.* 



February 20tli, 1912. 



Dr. A. 8mitu WooD\YAnD, F.R.S., Vice-President., 

 in tlie Chair. 



The Mimite.s of the last Scientific Meeting were confirmed. 



Dr. A. T. Mastkrman, M.A., F.Z.S., gave a demonstration, 

 ilhistrated by a large number of lantern-slides, of recent investi- 

 gations on Age-determination in the Scales of Salmonoids, with 

 special reference to Wye Salmon. 



Dr. H. Lyster Jameson, M.A., D.Sc, Ph.D., F.Z.S., read a 

 paper " On the 8tructui-e of the Shell and Pearls of the Ceylon 

 Pearl-Oyster [Maryaritifera vulgaris, Schum.) ; with an Ex- 

 amination of the Cestode Theory of Pearl Production." The 

 author began by reviewing the work on the subject of Pearl 

 Production carried out in Ceylon by Prof, llerdman, P.R.S., and 

 his successors. He examined the theory, enunciated by Prof, 

 llerdman, that most Ceylon "hue" pearls had for their nuclei 

 the remains of cestode larvae, and that these larvae, which arc 

 abundant in the liver and connective tissues of the Pearl-Oyster 

 in Ceylon, were the "cause" of the most valuable pearls. 

 Dr. Jameson maintained that the evidence adduced in support 

 of this theory by Prof. Herdman and Mr. llornell was insufficient, 

 and that the only drawings in Prof, llerdma.n's "Report on 

 the Ceylon Pearl-Oyster Fisheries," published by the Royal 



* This Abstrtict, is published by the Society at, it? ofTices, Zoological Gardens, 

 Regent's Park, N.W., on the Tuesday foUowiiig the dale of Meeting tu which 

 it rolers. It will be is.^ned, along witii the ' Proceedings,' free of extra charge, 

 to all FelU)ws who subscribe to tlie Publications ; but it may be obtained on the 

 day of publication at the price of tiixpence, or. if desired, sent post-free lor 

 the sum of Hix bhilling^ per annum, payable in advance. 



