THE HERRING FAMILY 171 



the drift-net boats seldom go much further than ten miles out. 

 The ripe pilchards are taken in small numbers in mackerel nets 

 in summer and early autumn. Possibly if pilchard nets were 

 habitually used at the proper places and time of year ripe 

 pilchards would be taken in large numbers, but the meshes of 

 mackerel nets are much too large to catch pilchards in the 

 ordinary way, the few that are retained by the meshes are caught 

 not behind the gills, as fish usually are in a dift-net, but round 

 the abdomen, which is swollen by the enlarged ovaries. As far 

 as my own experience goes only the females are caught in this 

 way, and I was for a long time unable to obtain a ripe male 

 pilchard. Probably the ripe males are not distended so much as 

 the females, and therefore pass through the meshes of the 

 mackerel nets without being retained. Probably, too, only the 

 largest females are caught. The number taken in a fleet of 

 mackerel nets at one time varies from one or two to fifty or 

 more, but scarcely ever exceeds a hundred. The time at which 

 they are taken is not limited to a few weeks, but extends from 

 the beginning of June to the end of October ; they are 

 commonest in July and August. 



The eggs of the pilchard when shed are not heavy and adhe- 

 sive like those of the herring, but float about separately in the 

 sea, like those of the sprat and anchovy. As early as 1865 

 Couch stated in his work on British fishes that he had reason 

 to suppose that the spawn of the pilchard was shed at the sur- 

 face, and floated in a quantity of tenacious mucus, but he gave 

 no satisfactory evidence on the subject. Mr. Dunn informed 

 the Commissioners for Sea Fisheries, in 1879, that he had 

 pressed ripe spawn from a female pilchard in May, 1871, and 

 that the eggs floated separately in a bucket of sea- water. But 

 no microscopic examination of the egg was made till many 

 years afterwards. In 1888 Raffaele, an Italian zoologist, de- 

 scribed among the eggs he found floating in the sea one which 

 evidently belonged to some fish of the herring family, and which 

 he thought probably belonged to the sardine. Not long after I 

 began to work at Plymouth I obtained from the open sea a 

 buoyant egg similar to that described by Raffaele, and found 

 that the ripe unfertilised eggs squeezed from female pilchards 

 had the peculiarities in the condition of the yolk seen in this 

 egg, and in no other egg hitherto examined from our seas. 



