RATE OF GEOWTH OF SOME SEA FISHES. 247 



It is thus conclusively demonstrated that in November last^ when 

 the year-old pilchards were taken in our nets, the mackerel were 

 feeding on younger pilchards 6 to 9 cm. in length (2*3 to 3"5 inches) 

 which were derived from spawn shed the previous summer. 



It seems probable that the pilchai'ds which are 13 to 16 cm. long 

 in November would reach the adult condition at a length of 20 or 

 22 cm. by the following summer, and would then breed for the first 

 time. I have not yet definitely ascertained that pilchards do breed 

 at the size just mentioned. I measured five ripe females in June, 

 1891, and they were from 23"7 to 24'8 cm. long, weighing from 

 5 to 5| oz. But probably if a large number of ripe specimens 

 were measured many would be found to be less than 23 cm. long. 

 I have measured samples of the ordinary adult pilchards taken for 

 the market at various times of the year. For instance, in — 



August, 1891, I measured fourteen specimens taken six or seven 

 miles off shore in Whitsand Bay ; eleven were females 21 cm. to 

 25"3 cm. long, in all of which the ovaries were small, and in many 

 apparently recently emptied; the other three were males 21*3 and 

 21*4 cm. long. 



November 3rd, 1891, I measured six specimens from a large 

 catch taken off Plymouth Sound : they were 21 cm. to 22*5 cm. in 

 length, two females, 4 males ; the generative organs in all very 

 small. 



The largest pilchard I have seen was brought to me in December, 

 1890, and measured 27^ cm. = 11 inches in length; it weighed 8^ 

 oz., audits generative organs were exti'emely small and rudimentary, 

 as though it had become sterile from old age. 



In my preceding paper on the pilchard in this Journal, and in an 

 article in Nature, January 14, 1892, I have referred to Professor 

 Pouchet's Reports on observations on the sardine made at Con- 

 carneau on the coast of Brittany. I propose here to give a more 

 extensive account and criticism of Pouchet's records, comparing 

 them with those I have made at Plymouth, in order to see if they 

 confirm, supplement, or modify the conclusions I have suggested 

 above as to the rate of growth. The records in question date from 

 the year 1887, only a few scattered observations having been made 

 before that time. I will give here a list of the publications in 

 which these records are contained : 



(1) Rapport sur le Fonctionnement du Labor atoire de Concarneau en 

 1887 et sur la Sardine, par M. G. Pouchet. Ministere de I'lnstruc- 

 tion publique et des Beaux-Arts. Paris, Imprimerie Nationale, 

 1888. 



(2) Le Begirae de la Sardine sur la Cote Oceanique de France en 

 1887, par M. G. Pouchet. Comptes Rendus, 20 February, 1888. 



