6 Fishery Board for Scotland. 



The mean of tlie major diameters (Mj) is 57'14:6 (2'28584 mm.), and the Standard 

 Deviation (o-j) = 1-7892. The mean of the minor diameters (M,) is 55-298 (2-21192 

 mm.), and the Standard Deviation (cto) = ] "67387. 



M - M 



jf -1 2^ J) ^g -^ o ^j^Qgg distributions are significantly different where 



o-Mi - M2 G J 



1-848 



Now, if G^V-M.= (S-+?r), ^^-^'= /3-201351 2-801863 = 16-86521. 

 VN, N,y CTM.-M, V~500~+~500~ 



Hence, although in a number of these eggs freed from the gelatinous material, 

 the two diameters at right angles were equal, and the eggs were therefore almost 

 spherical, the eggs of Loj)hius are tyjDically oval, the long diameter being significantly 

 different from the minor diameter. 



The following table shows the variable number of oil-globules in the sample of 

 500 eggs. 



Number of 

 Oil Globules. Frequency. 



1 45 



2 111 



3 111 



4 113 



5 71 



6 27 



7 17 



8 • 5 



500 



In addition, 38 isolated eggs caught at 58° N. ; 2° 54' W. on 4th April 1914 were 

 measured in the living condition. Two measurements at right angles to each other 

 were made on each egg ; the range was from 2-33 to 3-11 mm., and the mean was 

 2-72 mm. The number of oil-globules varied from one to nine, and the diameters 

 of the largest oil-globule ranged between -51 and -71 mm. 



These 38 eggs, when caught, showed no traces of developing embryos, and 

 although the eggs were kept alive as long as possible in fresh sea-water, no traces 

 of developing embryos appeared. Indeed, the eggs gradually died. In five days 

 after capture three eggs were dead at the bottom oJE the vessel ; in seven days the 

 total had increased to nine, whilst eleven days after capture, only six eggs 

 remained clear, floating at the surface of the water. Even in these, the germinal 

 disc showed no signs of segmentation, so that one may conclude that this particular 

 batch of eggs had escaped fertilisation. 



The eggs, when preserved in formalin, usually retain their pale yellow tint. 

 The following are the measurements of eggs so preserved. All the eggs, before 

 measurement, had remained more than a year in preserving fluid (-2 per cent, 

 formalin), so that practically they had reached their maximum shrinkage. 



Measurements of Isolated Eggs of Lophius piscatorius caught in the North Sea. 

 Size in mm. . . 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 

 Frequency . . 5 33 48 41 62 56 38 12 3 = 298 



The mean size is 2-4745 mm. The mean size of the oil-globule in those eggs which 

 contained only a single large oil-globule was -6718 mm., with a range from -52 to 

 •88 mm. 



Agassiz and Whitman (1885), in their description of the eggs of Lophius pis- 

 catorius from the American side of the Atlantic, state that the eggs are laro-e, meas- 

 uring 1-75 mm. in diameter, and that the single oil-globule is -40--42 min. The 

 eggs obtained in American waters would appear to be much smaller than those 

 obtained in Scottish waters. The American authors do not say, however, whether 

 the eggs were measured in the hving condition or after long immersion in pre- 

 set vinjg fluid. 



