154 REPRODUCTION AND GROWTH OF THE PJLOHARD. 



period is prolonged over five or six months, though the majority of 

 the fish spawn within two months. Marion squeezed the ripe eggs 

 from the fish into sea-water ; the eggs on leaving the ovary were 

 1*3 to 1"4 mm. in diameter, but after being in the water some hours 

 the great perivitelline space had been formed, and the eggs were 

 1*7 to 1*8 mm. in diameter, although they did not float. He 

 remarks that this is no proof that eggs perfectly healthy, living 

 and fertilized, do not float, while the vast perivitelline space estab- 

 lishes a great resemblance with the eggs attributed to the sardine, 

 being a rare character in buoyant eggs. Marion also obtained in 

 the Gulf floating eggs of the kind assigned by Raffaele and myself 

 to the sardine, and found them only at the time of year when the 

 sardines were ripe. Marion figures the egg and the larva hatched 

 from it, pointing out that the latter is undoubtedly a clupeoid larva. 



In the course of the past summer I made an attempt to finally set 

 at rest the question of the pilchard egg by obtaining healthy fertilised 

 ova from the parent fish by artificial fertilization. With this object 

 I went out in a mackerel boat on June 21st, and on June 22nd the 

 nets were shot about twenty miles to the south of the Eddystone, 

 that is nearly thirty miles from the coast. When the nets were 

 hauled I obtained in all about fifty ripe pilchards from them, but to 

 my disappointment found there was not a single male among them. 

 Probably the explanation of this is that the meshes of the net were 

 rather large, and that the males are not quite so swollen when ripe 

 as the females, and were, therefore, not retained. It must be pointed 

 out that these ripe pilchards are not meshed by the gills in a mackerel 

 net as the mackerels are, but are meshed round the abdomen, which 

 is greatly distended by the swollen ovaries. Pilchard nets are never, 

 so far as I know, used off Plymouth so far out at sea as spawning 

 pilchards are found. In fact, very little pilchard fishing is carried 

 on in June and July, and when it is recommenced in August and 

 September it is carried on almost exclusively inside the Eddystone. 

 (See Mr. Hoach^s records of pilchard fishing, this Journal, vol. i, 

 p. 388.) 



However, I squeezed some ripe eggs from the living female fish 

 I obtained into a bottle of clean sea-water without delay, and when 

 I examined them in the Laboratory a few hours afterwards I had the 

 satisfaction of finding nearly all of them floating- at the surface. 

 These floating eggs were in all respects similar to the eggs identified 

 as pilchard eggs obtained in the tow-net from the sea ; they were 

 perfectly transparent, the yolk in them consisted, not of yolk-spheres 

 as in the dead ova from the ovary, but of polygonal masses, that is 

 of yolk-spheres made polygonal by mutual pi-essure, as in the eggs 

 obtained from the sea, the large oil-globule was present and the 



