THE SCAD FAMILY. 165 



young are as long as one's finger, and that in two years they 

 reach the size of a herring, and are ' fully grown' in three years. 

 He states that for the h'rst two years they remain in the open 

 water near shore. 



The facts given by these observers can only be reconciled by 

 assuming that the ' young' of about 3 inches described by Dunn 

 must be about one year old, but a difference in length of from 

 3 inches in September to 6 or 7 in November makes the 

 continuity of the series rather improbable. 



Perhaps the series 4 inches 8 inches 11 inches may be 

 taken to express the average rate of growth of the mackerel in 

 the first three years of its life. Sexual maturity appears to be 

 attained at a length of 11 12 inches but individuals have been 

 known to exceed 18 inches in length. 



The Scad Family. Carangidae. 



THE HORSE-MACKEREL. (Caranx trachurus, Lacep.) 



Couch found the scad with ripe roe in the middle of 

 July, Day giving this month as well as June and August as the 

 spawning-season. In the Mediterranean, according to Risso, it 

 is earlier, viz. in spring. Holt found ripe males and almost 

 ripe females on the 16th June at Penzance. The eggs measured 

 84 mm. in diameter, with several oil-globules which, by and 

 by, fused into one. He imagined that they were pelagic, and 

 similar to those of the mackerel except in size. The oil-globule 

 is proportionally large. In September the bays in Cornwall 

 swarm with young, an inch in length, and in October about 2 

 inches long. Couch also observes that he has found them, not 

 exceeding an inch in length, in the stomach of various fishes, 

 from the end of December to the middle of February ; while he 

 has again seen them 3 or 4 inches in length in August and 

 September. Cunningham took similar specimens during the 

 same months. The spawning-period, therefore, as usual, would 

 seem to extend over a considerable time, but chiefly in June 

 and July. The fish is not uncommon, singly or in small 



