206 SEASON 1875-76. 



The table on page 205 shows the days the S. levenensis were 

 spawned, and on which each batch eyed and hatched, and the 

 calculated total percentages of incubation at each stage. 



The lot taken on November 6th were sold for the benefit of 

 the Loch Leven Angling Association, so the date of their hatching 

 is unknown. The lot entered on November 26th were brought 

 to the hatching-house at Middlethird on that day from Kinross, 

 and must have been spawned the day previous, and lain all night 

 in a warm cottage ; this will account for the apparently early period 

 at which they eyed. These eggs were the longest in hatching of 

 any this season, and this may also be due to their being kept over- 

 night without change of water. 



The only deduction at present to be made from this table is, 

 that it forms a useful and ready way to compare ova taken at 

 different times and laid down in the same hatching-house. It also 

 points to the percentage of incubation accomplished in any period 

 of twenty-four hours, at any given temperature, being the same 

 whether the ovum is in its early or late stages. It ought to have 

 been mentioned that the lot taken on November 26th was placed 

 in the last box in the house, and the water in February, when 

 the quantity was small, may have fallen below the calculated 

 average, and so the discrepancy not be so great as appears. 



I add the table, calculated to fifths, from- 40 F. to 48 F. 



TABLE OF PERCENTAGES OF INCUBATION (PER DIEM). 



Deg. Deg. Deg. 



40-0 1-000 43-0 1-176 46-0 1-428 



2 1-010 -2 1-190 -2 1-449 



4 1-020 -4 1-204 -4 1-464 



6 1-030 -6 1-219 -6 1-492 



8 1-041 -8 1-234 -8 1-500 



41-0 1-052 44-0 1-250 47.0 1-538 



2 1-063 -2 1-265 -2 1-562 



4 1-075 -4 1-281 -4 1-587 



6 1-086 -6 1-298 -6 1-612 



8 1-098 -8 1-315 -8 1-639 



42-0 1-111 45-0 1-333 48'0 1-666 



2 1-123 -2 1-351 -2 1-694 



4 M35 -4 1-369 '4 1.734 



6 1-149 -6 1-388 -6 1-754 



8 1-162 -8 1-408 -8 1-786 



