Table 5,--Frequencies of egg diameters of right and 
left ovaries from the same fish 
Class midpoint 
(micrometer (en Right Left 
7 ovary ovary 
units*) 
* 1 micrometer unit = 0.022 mm, 
Description of sampling procedure 
The following procedure was used in sampling the ovaries for egg diameter measurements, 
It should be pointed out that the difference of means anterio-posteriorly was not inspected when 
this procedure was chosen, (1) Across section about 1/4 inch thick was taken from an ovary 
(always from the middle and from the left ovary, whenever possible, for the sake of uniformity). 
(2) The ovary wall and the projections of this wall into the lumen were removed, (3) The section 
was placed in an 8-ounce jar about two-thirds full of 10-percent formalin and shaken in an agitator. 
(4) The contents of the jar were then stirred with a metal tube which had an inner diameter of 
12mm, An erratic motion was used so that the eggs would not move in circular stream. (5) The 
tube was then quickly lifted out of the jar and vertically plunged back, (6) The top of the tube was 
closed tightly with the thumb, and tube and contents were withdrawn. (7) Steps 4 through 6 were 
repeated several times. (8) The samples thus obtained were combined and broken down further 
by teasing. (9) A subsample was taken by means of a medicine dropper with an opening of | 
2,5 mm, at the mouth, (10) The eggs in this subsample were measured to the nearest 0,022 mm, 
under a dissecting microscope. 
