OCCURRING IN THE NEIGHBOURHOOD OF PLYMOUTH. 43 



nets, and that these were always soft and ripe, with spawn and milt 

 running out of them. I found by actual experience that this was 

 perfectly true. On June 2nd, 1888, two pilchards were brought up 

 to me fi'om a boat which had caught them in mackerel nets five 

 miles south-west of the Eddy stone. These were perfectly ripe, the 

 whole ovary, as in the herring, containing nothing but ripe eggs 

 whicli escaped on the slightest pressui-e. These eggs were, of 

 course, dead, and as these were the only two pilchards taken it was 

 impossible to fertilize any of them at the time of capture. But the 

 eggs were fresh enough to show in some degree their structure, 

 and I made a drawing of one which is shown in fig. 28. This 

 shows that there is but a single oil-globule, and that the yolk is 

 made up of spherical vesicles. The diameter measures '98 mm., 

 that of the oil-globule '16 mm. Of course the envelope in the 

 ovarian egg is everywhere in contact with, the yolk. Several times 

 in June and July one or two pilchards were taken by mackerel 

 fishermen wh.o were endeavouring to get fertilized pilchard spawn 

 for me, but they never succeeded in getting ripe males and ripe 

 females at the same time. Sometimes they got a single ripe male, 

 at others two or three ripe females. One boat shot at my request 

 two pilchard nets, which have a smaller mesh, with its fleet of 

 mackerel nets, but even this did not succeed. One of these occa- 

 sional ripe specimens, a female, was caught as late as October 17th, 

 and the skipper who took it pressed the ripe ova into a bottle of 

 clean sea-water, and gave them to me the next day when he 

 returned to port. But when I got them the ova were already 

 dead and lying at the bottom of the jar, and on examination I 

 found that the yolk was decomposed. I could form no conclusions 

 from these as to the normal extent of the perivitelline space. 



In 1887 I had taken pelagic ova in the tow-net, which, from the 

 probability of the ovum witb segmented yolk taken in the Firth of 

 Forth being that of Clwpea s-prattus, I guessed were those of the 

 pilchard. The structure of these ova is shown in fig. 29. I took 

 some in Whitsand Bay, August 11th, and did not meet with them 

 again till November 9th, when I found a few in a tow-net worked 

 from a trawler to the south-east of the Eddystone. On both occa- 

 sions there were only five or six specimens of this particular ovum. 

 Its diameter measured in one case 1'72 mm., in another 1*65, 

 including the envelope. The space between the latter and the yolk 

 was extremely large, and the yolk itself measured "85 mm. in 

 diameter in the first case, "95 mm. in the second. The yolk was 

 composed of polygonal segments divided by curved surfaces, and 

 contained a single oil-globule "16 mm. in diameter. This ovum, 

 therefore, agrees in every respect both of size and structure with 



