42 EEPRODUOTION AND DEVELOPMENT OF TELEOSTEAN FISHES ' 



from the open sea by means of the tow-net^ and has not taken directly 

 from the fish, eggs that could be identified with them. He therefore 

 speaks of tliem as Clupea species A, and Clupea species B. The first 

 of these he believes to be the ovum of the pilchard. It is well 

 known that the pilchard and the sardine are the same fish at different 

 sizes, and sardines are common enough in the Gulf of Naples. This 

 species. A, is an ovum of spherical shape varying from 1'50 to 1*70 

 mm. in diameter. Compared with the majority of floating ova, it 

 has this peculiarity, that the space between the egg proper and its 

 envelope is exceedingly large ; the egg itself inside this space has a 

 diameter of only '80 to "90 mm. In the yolk is a single oil-globule 

 '16 mm. in diameter. The segments of the yolk have a polygonal 

 form due to their mutual pressure. The egg hatched in four or five 

 days at a tempeiature of 9° to 12° C, and the larva resembled that 

 of other pelagic Clupeoid ova, e. g. the sprat, but its length is not 

 given. 



The ovum of species B differs very slightly from that of species A. 

 It is a little smaller in the diameter of the egg envelope, which is 

 1"20 to 1*40 mm. It has, like the other, a segmented yolk con- 

 taining a single oil-globule which is '121 mm. in diameter, slightly 

 smaller than in the previous case. The oil-globule has a slightly 

 yellow colour, the yolk and embryo have a faint smoky tint, which 

 colours are absent in species A. The only other difference is that 

 in the newly-hatched larva of species B the oil-globule is in the 

 centre of the lower margin of the yolk, in species A it is at the 

 posterior end of the yolk. Species A was found in the winter. 

 Species B in summer and autumn. 



My own Inquiries. — From the beginning of September, 1887, I 

 examined at Plymouth the pilchards landed by drift-net boats from 

 time to time, but never found any generative organs which were 

 quite ripe or very nearly ripe from that time till the following 

 summer. In October, 1887, the ovaries and spermaries seemed to 

 be about half developed in a few specimens, and it is possible, even 

 probable, as will be seen, that some individuals spawn late in the 

 autumn. I found no change in the condition of the fish up till 

 the end of January : the fish were usually 7^ to 8^ inches in 

 length. In the early part of 1888 I was too much occupied with 

 other fish to pay a great deal of attention to pilchards, but there 

 was no regular fishing for them going on, and scarcely any were 

 caught. I was told by a pilchard fisherman that these fish were 

 found in spawning condition in April and May, but he did not 

 think at any other time of the year. Afterwards I was told by 

 mackerel fishermen that they often in summer got large pilchards 

 which were meshed along with mackerel in their mackerel drift- 



