206 



Part III. — Sixteenth Annual Report 



Formula (1) shows the number of records of pelagic fish ova for each 

 of the six stations, thus : — 



{a) Inner Stations. (ft) Outer Stations. 



Numbers of the Stations, ... I. HI. IV. V. VIII. IX. 



Total number of Records for each Station, 16 11 14 22 21 26 



This formula exhibits a marked difference between the number of 

 records for the inner and outer stations, those for the outer stations being 

 considerably larger. The total numbers for each of the two groups of 

 stations are 41 and 69 respectively, showing a difference of 28 in favour 

 of the outer stations, which is equal to nearly 41 per cent. — a difference 

 which, as already stated, is doubtless owing to the outer stations being 

 nearer the more important spawning-grounds. 



Formula (2) shows the total number of records of pelagic fish ova for 

 each of the twelve months, for (a) the inner stations, I., III., and 

 IV.; {h) the outer stations, V., YIIL, and IX.; and (c) for all the six 

 stations : — 



Names of the Months, i'SS3Urt'i'5l?g--5o'^ 



r(^*) the Inner Stations, - 000 11 14 9330100 

 Scorarforeach^ " 2 6 6 13 18 8 7 7 0 1 0 1 



Month, for [(c) all the Six Stations, - 2 6 6 24 32 17 10 10 0 2 0 1 



The monthly maxima of the records of pelagic fish ova, as might be 

 expected, are to be found in the early spring and summer months, those 

 for April and May especially being considerably higher than for the other 

 months. The arrangement of the numbers to correspond with the inner 

 and outer stations brings out another contrast between them : for the 

 inner stations there are no records of fish ova till April, nor are there any 

 after October, but for the outer stations there are two records in January, 

 six in February and in March, and one in December ; while with the 

 exception of June the numbers for the five central months are consider- 

 ably above those of the corresponding months for the inner stations. 

 This seems to indicate that spawning outside begins at a comparatively 

 early period of the year, and may continue more or less over all the 

 months : inside the estuary, on the other hand, spawning is later in com- 

 mencing, and rarely continues beyond the month of August. It is pro- 

 bable that some of the ova collected at the inner stations may have 

 drifted in or been carried in by currents from the outside, but it is also 

 well known that there are a number of fishes, whose eggs float, that spawn 

 within the estuary, so that the majority of the records for the inner 

 stations are those of fishes that have really spawned there. 



The next Formula (3) shows the total number of records of pelagic 

 fish ova for each of the seven years for {a) the inner stations, (5) the 

 outer stations, and (c) for all the six stations : — 



1889. 1890. 1891. 1892. 1893. 1894. 1895. 

 T-^+oi r...r^\.c.y> r.f f {(^) '^^^^^ Statious, - 2 7 14 7 5 4 3 

 R^col^^^^^^^^^^ - J i '1 '1 1 1 1 



Year, for ^^^^ ^.^ Stations, - 5 15 30 25 13 11 12 



The largest number of records are those for 1891 and 1892. Another 

 point in connection with the distribution of the pelagic fish ova, as shown 

 by the published tow-net records, is the occurrence of them in several of 

 the bottom tow-net gatherings. The records show that pelagic fish ova 

 were found in bottom tow-net gatherings on eight diff'erent occasions, and 

 it is noteworthy that on a few of these occasions no fish eggs were 

 observed in the surface tow-net. This feature in the distribution of the 



