THE AGE OF FISHES AND THE RATE AT WHICH THEY GROW. 403 
is true, by means of which the rate of growth of these young stages may 
be investigated. During May, June and July a large net of fine mesh — 
the Petersen young-fish trawl—was used at frequent intervals, chiefly 
between Whitsand Bay and the Eddystone, for the purpose of collecting 
young stages of fish. Young Mackerel first appeared on the 25th of May 
and they continued to be caught fairly regularly until the end of June, 
whilst in July only three specimens of these early stages were found 
during the whole month. All the specimens captured were preserved 
and subsequently measured. The numbers taken at any one time were 
small, thirty-two being the largest number in a single haul of the net, 
but 1f we combine the figures obtained from the different hauls into two 
groups, certain interesting features appear. The following diagram 
represents the figures in a graphic form, the measurements being in 
millimetres! and each fish being represented by a dot :— 
Size in min. 
Te 
5 
1914. | 6 enial tetrerue éPe. hee 18 hg 
May 25th | Fete aes Lee EM cr Monty Els Derren OnOee ORO AIO 0y0. 20 3 
to June 3rd. eda lits. (Rte Eas ata | tap eS | a eae ae oO 
Weak? irs testa cs “2 Bae 14 
6 HAULs. | ergs abe 
| Neti ee 10) 
Average Size Wie ag! s Se : 
7°15 mm. | y : aA. 
Mode 6°5 mm. | 10)... 2 
oul 
Peet 
eel, 
| 5) 2 
6 50 
3 a 
UP cers essa ) 
June 10th-29th. | 9 
16 Haus. | SP tne 
tee sa Ch erect ene 6 
Average Size ae = 
| eve ieeseliel) «6 16) 40 ‘ 
BCS) a eaten ek 
Modes 6 5 and I) WO) Gio: oo 6 
9-5 mim. nee, Geet 
eee, ao 
1, 2 
poe 
13 
Fie, 1.—LArvAL MACKEREL. 
1 A table showing the relation between British and Metric measures will be found on 
p. 424. 
