1.S4 



of these eggs remained; the rest had all died, notwithstanding that I took care to 

 remove all dead eggs every day. 



The arrangement which I adopted and found perfectly satisfactory is shown in the 

 dia"ram, Fig. F. It may of course be carried out on any scale, and does not require 

 a great deal of space. It is better to increase the capacity of the apparatus by 

 increasing the number of the jars ratlier than by increasing the size. Jars larger than 

 those I have described become unwieldy. 



I found the method suited the hatched flounder larvae extremely well : they lived 

 in the jars in perfect health until the yolk was entirely absorbed. I did not succeed 

 in feeding them after that period. It would probably be necessary when the yolk 

 was absorbed to turn then out into a larger tank, as feeding in a confined space 

 contaminates the water. A few of tlie plaice eggs hatched on February 22, and 

 one or two of them lived till the yolk was absorbed in the apparatus arranged on thu 

 American method ; but this was the total result out of several thousand ova. 



To return to the eggs of the sole which I obtained in Mount's Bay on March 23. 

 I placed tliem in two hatching jars arranged in the way I have described. There 

 were several thousand of the eggs, but I did not count them. As I have said, they 

 were all fertilised and had commenced to develop when placed in the hatching jars. 

 On March 21, when I examined them, I found to my surprise that nearly half in 

 each jar were dead. The blastoderm in the dead ones was formed, but some abnormal 

 appearances were seen round its edge. I removed the dead eggs, and hoped the 

 mortality was over and that the rest would live. But the next day I found again 

 half of those left had died. In the living ones the germinal membrane had enveloped 

 more than half the yolk : nuiny of them seemed unhealthy. On March 26, only about 

 six eggs in each jar were left alive, and these were dying, although in them the 

 embryo was already formed. As I had succeeded in keeping eggs of the sole, 

 artificially fertilised, ahve for a considerable time with only the roughest apparatus, 

 and as I afterwards hatched eggs taken by the tow-net from the sea, the cause of 

 death in the above experiment clearly could not be attributed to the water of the 

 a(juarium or any of the conditions under which the eggs were kept after they were 

 brought to the Laboratory. I could only attribute it to the railway journey which 

 had shaken and jolted the eggs and so injured them mechanically. It might be 

 su^o-ested that there was too great a dillerence of temperature between the water in 

 which the eggs were carried from Penzance and the water of the hatching jars, but 

 other experiments showed that eggs taken from the sea lived well in the sea water of 

 the Laboratory, and the weather during the railway journey was neither hot 

 enouo-h to heat the water in the jars containing the eggs nor cold enough to cool it 

 to any extent. 



Believing it useless to carry fertili-sed eggs by rail, I went out on April the 8th, on 

 board a trawler which was going to fish on the Mount's Bay ground. On April 11, 

 12.5 a.m., the trawl was hauled with seventeen soles in it. Of these I examined 



