44 EEPRODUCTION AND DEVELOPMENT OF TELEOSTEAN FISHES 



Raffaele's Clupea species A. Of those taken on November 9th I 

 was successful in hatching some, and the appearance of the larva 

 produced is shown in fig. 30. This larva was 3'8 mm. in length, 

 and the oil-globule was at the posterior and lower side of the yolk, 

 thus also agreeing with the larva of Raffaele's species A. There 

 can be no doubt that these ova of mine and those described by 

 Raffaele as species A belong to the same species of fish, and the 

 character of the unfertilized ovum taken directly from the pilchard, 

 having a diameter corresponding to that of the yolk in the tow-net 

 specimens, and an oil-globule of exactly the same size as that in the 

 latter, is sufficient evidence that these ova from the tow-net are the 

 ova of Clupea pilchardus. Fig. 30, then, shows the structure of the 

 lai-va of the pilchard. Like that of the herring and sprat it has a 

 unicolumnar notochord, that is, a notochord with a single linear 

 series of cubical vacuoles. At the time of hatching, pigment, as in 

 the herring, is altogether absent, even in the choroid of the eyes. 

 The intestine extends far behind the yolk, and the anus is near the 

 end of the tail. A comparison of figs. 28 and 29 shows that the 

 ovarian ovum of the pilchard is more closely similar to the fertilized 

 ovum of the herring than the pilchard ovum in its pelagic state 

 after fertilization ; in the ovarian ovum the yolk elements or seg- 

 ments are still spherical vesicles as in the herring, while in the 

 fertilized ovum these segments have come into close contact with 

 one another, and so become more polygonal. 



These observations show, as was previously stated by Mr. Dunn, 

 that pilchards spawn far out at sea, and that the pilchard fishery 

 consists exclusively in the capture of fish which are not spawning, 

 of fish in which the generative organs are not even approaching the 

 ripe condition. The shoals of pilchards which are caught in drift- 

 nets not far from shore in autumn, winter, and spring, approach 

 the coast to feed and not to spawn ; they are either shotten fish or 

 young fish which have never spawned. It is otherwise with the 

 mackerel and the herring ; mackerel ai'e, as I have shown in this 

 paper, caught as abundantly during their spawning period as at any 

 other time, while the winter fishery for herrings near Plymouth 

 and all the other great herring fisheries that I know of consist 

 chiefly in the capture of spawning shoals, although there are pro- 

 ductive fisheries of immature herring which I'emain some time in 

 shore waters for the purpose of feeding. 



My evidence, as far as it goes, does not favour the theory that 

 there are two separate periods in the year at which pilchards 

 spawn ; it shows that ripe specimens occur to the south of the 

 Eddystone occasionally from the beginning of June to the middle 

 of October, and as it is reasonable to suppose that the pilchard, like 



