532 MR. H. PKYER ON THE [Nov. 18, 



1 . An Account of a Visit to the Birds' -nest Caves of British 

 North Borneo. By H. Pryer, C.M.Z.S., &C. 1 



[Received October 16, 1884.] 



In March last I visited the island of Borneo, and during my stay 

 at Elopura determined to ascertain if possible the substance from 

 which the Swift makes the edible nest, so much prized by the Chinese. 



1 In illustration of this paper Mr. Pryer sent specimens of the Swift 

 referred to, and of its nest and eggs, also of the alga on which the bird was 

 supposed to feed, and of the Bat which inhabits the same cave. 



The Secretary stated that the Swift had been determined by Mr. Sharpe to 

 be Collocalia fuciphaga, and the Bat by Mr. Dobson to be Isyctinomus plicatus. 



The Secretary also read the following letter and Report addressed to him 

 upon this subject: — 



British Museum (Natural History), 



Cromwell Road, South Kensington, S.W. 



29th October, 1884. 



Dear Sir, 



The alga contained in the bottle you left with me is a species, probably 

 new, of Glococapsa. The individuals are of microscopic dimensions, and may be 

 found in great numbers composing the dark-coloured layers on the surface ex- 

 posed to the air ; the lighter-coloured, somewhat gelatinous mass consists of the 

 dead cells of the Gloeocapsa gradually accumulated beneath the upper layers. 

 It is only under the influence of reagents that the remains of structure are 

 displayed in this mass and its true nature discovered. 



Species of this genus are common on damp rocks and walls of caves, but I 

 have never seen any occurring in such masses as this one. I may mention, 

 however, as a remarkable coincidence that I have seen an allied species of Glceo- 

 capsa, covering with a thick coating the walls (high above high-water mark) of 

 a sea-cave a few miles to the north of Arbroath. This cave was inhabited by 

 numerous pigeons, and I was in the habit of frequently climbing into it when a 

 boy for the purpose of capturing the young pigeons in their nests in the roof. 

 The Glcencapsa (as I subsequently determined it) impeded me in this operation, 

 and to the best of my recollection it grew very abundantly on the old excre- 

 ment of the birds. Whether the excrement formed a specially suitable nidus 

 for the alga it would be interesting to discover in regard to the present case 

 — in which at all events the alga seems to assist in forming a nidus for the bird .' 

 I have examined a portion of a nest sent me by Mr. Holmes, of the Pharmaceu- 

 tical Society's Museum, without finding any trace of the alga in it. 



I have retained a small portion of the alga for the purpose of further deter- 

 mination, and I hope to have the means of comparing it with the one I refer to 

 above. Yours &c, 



GEORGE MURRAY. 



Beport on the Edible Birds'-nest. By J. R. Green, B.A., Assistant Demon- 

 strator in the Physiological Laboratory, Cambridge. 



The specimen gave no evidence under the microscope of any distinct vegetable 

 structures, and similarly gave no chemical evidence of either cellulose or any other 

 distinctly vegetable product. All the reactions went, to prove that the great 

 mass of the substance was -mucin, and such microscopic features as were apparent 

 confirmed the view that the nest was formed of strings of mucus plastered together. 

 The mucus when separated out gave some reactions, different to a certain extent 



