376 
BATHYMETRICAL SURVEY OF 
Examined at different seasons, the colour was found to vary. In 
October, 1903, it was very red; in May, 1904, dull brown; in January, 
1905, green. On all these occasions the phantom larva was about 
equally abundant, and none was seen in a more advanced stage of 
development. The changes of colour are doubtless correlated with the 
predominance of one or another organism. The A. valga is not always 
red ; in May, 1903, it was dull grey in colour. When algae are swarming, 
the colour will incline to green. The colour may be affected by the 
development of certain entomostraca — Diaptomus gracilis^ for instance, 
was very abundant, but quite colourless, in May, 1903. Later in the 
year it becomes brown or red. 
There are other ponds in close proximity to the Red Lochan, but 
none of these shares the turbidity and reddish-brown colour. The 
peculiarity is probably due to its being more closely shut in. The 
surrounding rim of gravel is 14 feet above the pond at its lowest part. 
There is, besides, a fringe of birch trees. The water is stagnant, which 
favours the growth of certain organisms, particularly Anurcea valga. 
The blood-red larva of Chironomus, though abundant, could have no 
part in causing the red colour, as it was not in the open water, but 
among the weeds and mud. 
Mr. Robertson, the keeper at Fersit, to whom we are indebted for 
several collections and much information about the loch, states that it 
is later in freezing than the other ponds in the region. The more 
active decomposition in the stagnant water would account for this. 
The temperature of the water in May is about 45°'0 Fahr. It is 
said that wildfowl never settle on this pond, and that the common frog 
cannot live in it. 
The following legend was related to Sir John Murray concerning 
this Red loch : — 
Many centuries ago there lived in these parts a noted hunter named 
Donnuil. In return for some services rendered to the witch of Ben-a- 
Vreich, she offered to deprive the deer either of the sense of sight or of 
smell, so far as he was personally concerned. He chose to have the deer 
deprived of the sense of smell, ‘ for,’ said he, ' I can easily cheat their 
eye.’ The witch, however, told him that in the stomach of the last stag 
he would kill there would be found a ball of worsted thread. As time 
passed Donnuil became ill, and, while weak in bed, his daughter told 
him a fine stag was caught by the horns in some bushes near the house. 
He asked for his cross-bow, and, although in bed, he shot the stag 
through his bedroom window. Later on his daughter brought him a 
ball of worsted which had been found in the stomach of the stag. He 
knew his end was near; indeed, he died the same evening. On the 
following morning the Red Lochan had appeared at the place where the 
stag was killed.” 
This story was evidently invented to explain the origin of the Red 
