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Dr. A. B. Griffiths. On the [June 16 y 



XVI. " On the Nephridia and ' Liver ' of Patella vulgata." By A* 

 B. Griffiths, Ph.D., F.R.S. (Edin.), F.C.S. (Lond. and 

 Paris), Principal and Lecturer on Chemistry and Biology, 

 School of Science, Lincoln. Communicated by Sir Richard 

 Owen, K.C.B., F.R.S. Received May 20, 1887. 



Patella vulgata (Limpeb), with its conical shell adhering to the rocks 

 of our coasts, is well known to every sea-side wanderer. This member 

 of the Gasteropoda has been the subject of many scientific memoirs 

 in ancient and modern times. Amongst naturalists, Aristotle was the 

 earliest who gave an account of some of the limpet's habits, and 

 Cuvier was the first to describe its anatomy. In this paper the author 

 intends to describe the chemical properties of the secretions of two 

 problematical organs of this interesting little Gasteropod. 



The author has already proved the renal function of the green 

 glands of Astacus fluviatilis (' Boy. Soc. Proc.', vol. 38, p. 187) ; also, 

 in conjunction with Mr. Harold Follows, F.C.S., the renal function 

 of the organs of Bojanus in Anodon (' Chemical News,' vol. 51, 1885, 

 p. 241 ; ' Chem. Soc. Journ.,' vol. 48, 1885 [Abstr.], p. 921). Since 

 the publication of those papers, Dr. C. A. MacMunn (' Journ. of 

 Physiol.,' vol. 7 [No. 2], p. 128) has extracted uric acid from the 

 Malpighian tubules of insects and from the nephridia of the Pulmo- 

 nate Mollusca. 



I. Nephridia of Patella vulgata. 



The nephridia of Patella vulgata consist of two parts, left and 

 right lobes. The left nephridium is very small in comparison to the 

 right nephridium. The anatomy and histology of these organs have 

 been fully described by Prof . Lankester, F.R.S. ('Ann. Mag. Nat. 

 Hist.,' vols. 20, 1867, and 7, 1881), J. T. Cunningham (' Quart. Journ. 

 Microsc. Sci.,' vol. 22, p. 369), and Harvey Gibson (' Edinb., Roy. 

 Soc. Trans.,' vol. 32, pp. 617—620). 



After dissecting the nephridia from the bodies of a large number of 

 fresh limpets, the secretions of the left nephridia were examined 

 separately from those of the right nephridia. 



Both secretions were examined chemically by two separate methods 

 as follows : — ■ 



(a.) The clear liquid from the nephridia was treated with a hot 

 dilute solution of sodium hydrate. 

 On the addition of hydrochloric acid a slight flaky precipitate is 

 obtained after standing for some time. These flakes when 

 examined microscopically are seen to consist of small rhombic 

 plates and other forms. On treating the secretion alone with 

 alcohol, rhombic crystals are deposited which are soluble in water. 



