COUNCIL — JULY 1905 — APPEND. E 90 
1904, showed, that when the ground-rope of the ordinary otter-trawl was weighted 
by a chain (50kg.), four times as many flatfishes were taken as when the ground- 
rope was not weighted. In the summer, June and September, on the other 
hand, five comparative experiments were made which gave varying results. In 
most, the weighted ground-rope captured more than the unweighted rope, but in 
two, considerably more flatfish were taken by the unweighted than the weighted 
ground-rope. : 
It is useless to discuss the causes of these differences, until further experi- 
ments have been carried out and more details regarding the conditions under 
which the experiments have been made are given. 
The problem undertaken by England, namely, to determine the part played 
by the different parts of the trawl-net (beam-trawl) in permitting fish to escape, 
has also proved exceedingly difficult of solution. The method adopted in carrying 
out the experiments was to cover the various parts of thenet: square, batings and 
cod-end with separate nets of finer mesh. During the first series of experiments, 
the whole trawl was completely covered by these finer nets, and by far the 
greater portion of all the fish captured was taken in the covering net over the 
central part (batings) of the main net. In the later experiments, however, the 
covering nets in front were reduced in size, and relatively more fish were taken 
in the nets covering the hinder part (cod-end) of the main net. As this difference 
may have been due to the influence of various factors: depression of central part 
of net or greater resistance to towing, caused by the covering nets, etc., it is 
advisable to await further results before describing them in detail. 
It seems clear, nevertheless, from the English experiments already made, 
that more fish are able to escape from the trawl than are caught in it. Of the 
various species captured, the round fishes, as cod, haddock, gurnards, weevers etc. 
are naturally more able to make their escape from the main net than the flat- 
fishes; as a general rule, in fact, far more of the roundfishes escaped than were 
captured. Of the flatfishes, the dab (P. Zimanda) is the one which escapes in lar- 
gest proportions. The plaice (P. platessa) on the other hand, seems the most 
readily captured, though large numbers may sometimes escape. Thus, in the two 
richest hauls (X and XI) ca. 3000 plaice were taken in the main net whilst 797 
had escaped into the covering nets. 
To conclude this report, the practical and scientific importance of the 
