260 DR. H. LYSTER JAMESON ON 

[ From the PROCEEDINGS OF THE ZOOLOGICAL Soctery OF Lon pon, 
1912.) 
| Published June 1912. : 
Studies on Pearl-Oysters and Pearls.—I. The Structure 
of the Shell and Pearls of the C eylon Pearl-Oyster 
(Margaritifera vulgaris Schumacher): with an Exami- 
nation of the Cestode Theory of Pearl-Production. By 
H. Lysrer Jamuson, M.A., D.Sc., Ph.D., F.Z.S. 
(Plates XX XTIT-XLVII. and ‘Text-figures 33-41.) 

CONTEN'S. Page 
(1) Introduction ......... BES rh academe eC 260 
& Outline of the recent ies iceations m ( neyo Seo cide TUBERCLE eee aca 4 mee) 
(3) Professor Herdman’s Conclusions on Pearl-Pormation ..................... 268 
(4) Examination of the Cestode Theory of Pearl-Produetion —....... 271 
(5) Description of the two Globular Cestode Larve from the Ceylon Poa 
Oystererre 290 
(6) Opsetounens on the Seane ture ee the TabEOue (Coy jieeisunlhae the 
Cestode Larve: in Margaritifera vulgaris ....2.22...200c02-sereceerssee., 298 
(7) Materials available for the Present Investigations ........0.....0..........2, 294 
(8)) Methods” 2. --5.-..- ER AER SRS MRE wines a)” WAS?) 
(9) Structure of the hell cuberanees Feniadiat ete sie doe Caat ERC ERE A ee ne eee OO 
aes HW LherShellesecretame wl pitiheliay eee ss eceecnesceerercae ere nee eee eee meme Od 
(11) Shell-Secretion So ca tatteacceneatie aloe 
(12) Abnormal and Pathologic al Pinsee) a ale Shell- Sobetanee Tkcaest ee OL 
(3), Viarretres: of CevlonsRearlsscc ete seatess reat c incceemececenes ota een eee Somme, 
AV Miuscle=Pearl'S|t possccottnccs pcr once: ence neon eee eee TT 
B. Parenchyma-Pearls (“ Cyst-Pearls,’” Herdiman) .................. 330 
(14) Descriptions of the Centres of Individual Pearls .............................. Bol 
ACS Materraleimomuthe bersvanuGilis asda poeet ete eek aes eee ai 
B. Pearls purchased in Ceylon ............ = See cneraterenteas “Os 
©. Professor Herdman’s Slides........... Aactaenana doe. stereo! 
ID. Unlabelled Pearls (dry) in the British Maseant= eee BET 
K. Collection of Pearls given to me by Mr. Max May (ee eer: 338 
Kk. Collection of Ceylon Pearls given to me by Mr. E. 
lop kins yeeeeeeeeee . 339 
G. Pearls from Margar befor al Nealon is om ibe Gulf bf ikea 341 
H. Pearls from WM. vulgaris trom the Mediterranean ............... 348 
I. Pearls from M. vulgaris from New Caledonia .................. 843 
J. Pearl from M. vulgaris from Nossi-Ré, Madagascar on 344. 
K. Pearls from the Lapi shell (1/7. a ie from the edhe md 
Islands, Papua ........ : 344, 
~L. Pearls trom Placuna placenta ore Take Tampalakin umam, 
Ceylonmeer Sees B45 
M. Pearls from M. as tn var. eumingit esyer aha 
Black-edged Mother-of-Pearl] pans from Seana Gam- 
bier Archipelago ......... 346 
(25) SGeneral Summary eects cde se See eee neti els staat ee] 
(16) Works referred! Goer create ie ston ac te cena seme enectiec acl eetciye, occa eE eee mms L 
(17) Explanation of the: Platestgteyesce.cceen tne re eee teen coer olccerentnaee se pee ee mmO DE 
(1) Inrropuction,. 
The studies which are embodied in this paper have been deferred 
and interrupted. When Professor Herdman published his Report 
[2 
