TRANSACTIONS OF SECTION D. 679 



tions of yeasts, bacteria, &c. ; it must also Ibe firm, strong, and readily taken to 

 pieces and sterilised by beat. 



He bas accomplished this by taking; a piece of thick-walled glass tubing, about 

 ^ incb in diameter and 3 incbes long ; the two ends are softened and slightly drawn 

 to narrow tubes, not too thin. The piece of glass now looks like a narrow tube with a 

 tbick- walled bulb in the middle. One face of this central bulb is then ground flat, 

 until a bole about ^ incb in diameter is cut through ; a similar hole is then ground 

 in tbe opposite face of tbe bulb. The apparatus is now ready to be put togetber. 



It is sterilisedat 150° 0., and cemented by paraffin (or by gelatine in acetic acid), 

 by one of the ground faces, to a broad glass slide properly sterilised. Sterilised cot- 

 ton-wool is stuti'ed into the two narrow tubulures, and tbe banging-drop culture, 

 properly prepared on a sterile coverslip is cemented (by means of sterilised oil, 

 vaseline, or paraffin, &c.) over tbe upper hole of the chamber. 



The apparatus is now ready for use if the culture is required in air only ; a 

 slow diflusion of air and retardation of evaporation may be insured by simply wet- 

 ting the cotton-wool in tbe tubulures with pure water. 



If it is necessary to pass gases into the culture, one of tbe stuffed tubulures is 

 connected by means of caoutchouc tubing (sterilised in corrosive sublimate, abso- 

 lute alcohol, and boiling) with the appropriate gas apparatus. The pressure can 

 be regulated by the stuffing in this, the proximal tubulure, and by clip or screw- 

 taps. The stuffed exit tubulure is also protected by caoutcbouc tubing and a clip. 



If a very strong cover-slip and careful cementing are employed, the autbor finds 

 tbat a very good partial vacuum can be obtained, and even retained for some 

 hours. This is A-ery useful in cases where it is necessary to remove the oxygen or 

 carbon-dioxide from tbe imprisoned atmosphere. This may be accomplished more 

 or less readily by attaching bulbs containing an alkaline solution of pyrogallic 

 acid, or a solution of potassium hydrate. Obviously the apparatus can also be used 

 for testing the effect of poisonous gases, or for observing the action of light of 

 different intensities, or of various low temperatures, and so forth. Obviously, also, 

 it may be used for testing the action of different coloured lights, and of darkness, 

 &c., with certain simple modifications, e.ff. employing different coloured glass 

 tubing, or opalescent or blackened glass for making tbe culture-chamber, and 

 adding various screens, covers, &c., as required. 



10. On some Simple Models illustrating the Vascular System of Vertebrates. 

 By Professor W. N. Parker. 



11. On the Progress of the Investigation of the Natural History of the 

 Friendly Islands. By J. J. Lister. 



At tbe meeting of tbe British Association at Bath in September 1888, a Com- 

 mittee was appointed for the purpose of taking steps for the investigation of the 

 Natural History of tbe Friendly Islands and other groups in the Pacific visited by 

 H.M.S. Efieria. 



I was then starting to join the Egeria, and a grant of 100/. was voted to assist 

 me in carrying out tbe object of tbe Committee. At tbe next meeting tbe Com- 

 mittee reported tbat I had joined the Egeria on ber arrival at Tonga and was 

 carrying on my researches. 



I beg leave" to offer the following brief account of tbe further steps that I took 

 in pursuance of my object. 



H.M.S. Egeria arrived at Tongatabu on IMay 23, 1889, and after a short visit 

 to tbe neighbouring island of Eua, I left Tonga for a cruise among the islands 

 lying to the northward, between Tongatabu and the Equator. 



In tbe course of this cruise the Egeria called twice at Samoa, and also visited 

 Viti Levu, the principal island in Fiji, and made surveys of Fakaofu in the Union 

 Group, and Canton (or Mary) Island in the Phoenix Group, besides touching at 

 several of the neighbouring islands. 



