1897-98.] Migratory Movements of Salmonidce. 
49 
The Talla is a comparatively small stream about 6 miles in 
length, which joins the Tweed at Tweedsmuir. Ascending the 
main river it is, however, the last tributary of importance. Its 
drainage area is 6180 acres, being one-fourth of the drainage area 
of the Tweed above Talla-mouth. The observations as to state 
of the water are distinguished under the headings of “normal,” 
“ J-flood,” “ J-flood,” “ f and full flood.” In recording fish, salmon 
and sea trout are alone mentioned, no distinction being drawn 
between salmon and grilse. In all probability, however, few grilse 
reach these head waters, situated as they are, 90 miles from the 
sea, and visited by late-running fish only at the spawning season. 
Except when the stream was in full flood no difficulty was 
experienced in counting the fish, since the channel is beautifully 
clean, and the stream comparatively small. Even in half-flood the 
water was, as a rule, only slightly coloured. In counting, however, 
it is quite certain that in many instances the same fish was recorded 
twice or three times over. This could not be avoided by the 
watchers, and in dealing with the returns I have thought it better 
not to attempt any separation. 
Fish were recorded as in Talla Water from 4th November 1896 
to 16th February 1897, that is, during a period of 105 days, but 
fish were not observed, and were not present, on every individual 
day. The state of the water during those 105 days was as 
follows 
Normal flow during 75 days, including 8 days “frozen.” 
The number of days, included in the above list, on which no 
fish were recorded was 47. The state of the water during those 
days was as follows : — 
^-flood 
J-flood 
j or full flood 
105 
Normal flow, . 
J-flood, . 
J-flood, . 
f or full flood, 
34 
1 
7 
5 
47 
YOL. XXII. 16/3/98. 
D 
