1908] Eitter— Bailey — Weight of Developing Eggs. 7 



large oil drop noted in fresh laid eggs. Of this first lot, more- 

 over, a large percentage had died from the attacks of bacteria in- 

 other organisms. With the few remaining - I carried on the ex- 

 periment, so the results are in no way complete. 



The method of weighing was as follows : The eggs were counted 

 and each lot kept in a separate dish supplied with running sea- 

 water which had been filtered through No. 20 silk bolting-cloth 

 to remove dirt and small organisms. Each day the eggs were 

 counted out into a beaker of filtered sea-water which had been 

 warmed to 27 C. and allowed to cool to 25 C. After remaining 

 here a few moments for the whole to come to constant temper- 

 ature, the eggs were transferred to the weighing tubes by means 

 of a large mouthed pipette. 2 



The tubes were immediately weighed to tenths of a milligram 

 and the eggs at once returned to the hatching dishes. The tubes 

 were thoroughly rinsed in distilled water and dried in a calcium 

 chloride dessicator until the next weighing. Obviously the method 

 of weighing in sea-water would show variation in weight only 

 where the material lost or taken up had a specific gravity differenl 

 from that of the water. The following is a table of the weighings 

 made : 



- I made these tubes by sealing a piece of thin glass tubing at one end 

 and fastening it upright to a cover-glass with a bit of warmed paraffin. 

 The open end of the tube was ground and provided with a small cover-glass. 

 The eggs and sea-water were carefully introduced until the water came just 

 to a level with the open end of the tube; then, by closing off with the cover- 

 glass, a constant volume was obtained for each weighing. 



