APPENDIX I 139 



only one moor has been formed which reaches this exceptional standard, and that moor 

 is affected by abnormal circumstances.^ 



The fact that no district is immune from " Grouse Disease " is proved by the two 

 maps which are reproduced at the end of the series. These maps show approximately 

 the districts in England and Scotland respectively from which authentic Eeports of " Grouse 

 Disease" have been received during the past thirty-eight years. Where reports were 

 received from the same centre in more than one year additional dots were marked as 

 close as possible to the correct spot upon the map, and thus, though the maps are useful 

 as showing the general distribution of mortality, they must not be regarded as a reliable 

 guide to the exact position of the moors on which the outbreaks occurred. 



In spite of the fact that the reporting in some centres was better organised than in 

 others, it will be seen that during the period under review the mortality has been impartially 

 distributed amongst the Grouse-producing districts of England and Scotland, and more- 

 over that it bears an exact proportion to the importance of each district from a sporting 

 point of view. Thus it will be seen that on the finest Grouse ground of Caithness, Eoss, 

 Inverness, Banff, Aberdeen, Forfar, Perth, Argyll, and the Border counties disease has 

 occurred more frequently than in the lightly stocked areas of the same countries, while from 

 the extreme west coast and the deer forests of the Central Highlands little or no mortality 

 has been reported. The map of Northern England shows the same results, though not quite 

 so conclusively, since the reports from that country are less complete than from Scotland. 



" Grouse Disease " then is not confined to any particular geogi'aphical area, but seems 

 to bear a relation to the number of Grouse in each moorland district, and the maps 

 accordingly form an interesting record of the districts in which the largest numbers of 

 Grouse are to be found. 



An attempt has been made to trace a connection between the numbers of Grouse, and 

 their liability to " disease " in a particular district, and the geological formation or 

 meteorological conditions in that district. So far as geological formations are concerned 

 there does not appear to be any close connection. The best Grouse-producing district 

 in Caithness has a mineral sub-soil of old red sandstone on the east and granite on the 

 west ; Sutherland, in addition to the above-named rocks, has oolites and gneiss, Easter Eoss 

 consists principally of old red sandstone. The famous Grouse moors of Strathnairn, 

 Strathdearn, and Badenoch lie principally on a bed of gneiss or gneissose rocks ; the 

 equally productive moors of Upper Banffshire on quartzite, mica schist, and graphitic 

 mica schist with smaller areas of old red sandstone and granite. The upper districts of 



' The moor in question is Tentsmuir in the county of Fife. A stretch of sandy soil of about 1,000 acres 

 lying on the edge of the Nortli Sea, and only a few feet above higli water mark — it has a good but somewhat 

 irregular growth of heather. Until 1872 there were no Grouse on the moor, liut in that year a few wild birds 

 were turned down, and speedily became established. The moor now yields an annual bag of from forty to 

 sixty brace. This moor is entirely free from any ajipearance of Strongylosis, and the Grouse obtained from 

 it are the only Grouse examined liy tlie Committee which, on dissection, show no trace of the Strongyle worm. 

 The absence of this parasite maj- be due to the fact that the moor is isolated from other Grouse ground ; but 

 this can hardly be the correct explanation, seeing that the original wild liirds by which the moor was 

 stocked must presumably have Ijeen infected with the normal quota of this nematode. A more probable 

 explanation is that the salt from the sea spray has so impregnated the ground as to make it impossible for 

 the worm to exist, for it has been proved by experiment that even a mild solution of salt is fatal to the 

 Strongyle in the larval stage. On the other hand, hand-reared Grouse are often entirely free of the 

 Strongyle worm, and it is for this reason that they are the only birds which can be usefully employed for 

 experimental purposes. (Vide Ajipendix G.) 



