338 THE ZOOLOGIST. 



parasites. A round worm (or nematoid) he believed to be the 

 cause of the disease. Such a worm is constantly found in 

 grouse, while tape-worms were also credited with helping a fatal 

 result. But the parasitic theory is disposed of on the simple 

 ground that hardly a grouse is found to be free from worms in 

 its digestive system; and perfectly healthy birds (using the 

 word " healthy" in the ordinary sense of the term) are found 

 to possess both forms of worms independently of any symptoms 

 of grouse-disease. Both Mr. Colquhoun and Dr. Macdonald 

 in turn deal with secondary causes of the disease rather than 

 with primary conditions. They regard the weakening of the 

 bird's constitution by such causes as bad seasons, insufficient 

 food, and over-stocking as the prime factors in inducing the 

 ailment ; but such opinions, while deserving of consideration, 

 leave the idea of a specific cause undiscussed. The fourth 

 and fifth investigators are Dr. B. Farquharson and Dr. Andrew 

 Wilson. In 1874 Dr. Farquharson expressed the belief that 

 grouse-disease was " an epidemic and infectious fever." Dr. 

 Andrew Wilson, as the result of his independent dissections 

 and observations made about the same period, refuted Dr. 

 Cobbold's views, and in a paper (from which Dr. Klein 

 quotes) read before the Medico-Chirurgical Society of Edin- 

 burgh, and subsequently published in the * Edinburgh Medical 

 Journal,' showed that the disease was characterised by in- 

 flammatory symptoms of the respiratory and digestive organs. 

 He laid particular stress on the inflamed state of the lungs 

 in diseased birds, and suggested that the ailment was of an 

 infectious type. 



Dr. Klein now comes into the field, armed with the latest 

 methods of germ research. He finds the views of Dr. K. 

 Farquharson and Dr. Andrew Wilson to be those which best 

 harmonise with the facts. He confirms the evidence obtained 

 by Dr. Wilson after repeated dissections of diseased birds ; and 

 the grouse-disease has thus at last passed from the limbo of 

 obscurity, and has come to rank as an infectious malady, owing 

 its existence to the multiplication in the bodies of the birds of a 

 specific germ whose conveyance from the sick to the healthy 

 grouse accounts for the spread of the ailment. 



A thorough examination of the symptoms and characters 

 of the grouse-disease shows that it is an ailment due to the 



