288 THE JOURNAL OF ROTAN1* 



H1E11ACTUM AUKANTIACUM L. : 



a Case of Protective Colouration. 



Bv Miller Christy, P.L.S. 



Mr. Pugslei's recent article on this plant (Journ. Hot. 1921, 

 60-69) has called to my mind certain observations 1 made many 

 years ago in connection with it. 



I spent the summer of 1882 in the Engadine, where a form of the 

 {►hint grows in immense abundance in the meadows in the bottom of 

 the valley, beside the River Inn, at an elevation of about 6000 feet. 

 Evei'vone familiar with these meadows will be able to recall the 

 amazing profusion of Mowers of many kinds to be seen in them at the 

 height of summer. Yet even more surprisingly abundant than the 

 flowers is the almost inconceivable number of butterflies which 

 frequents the same meadows at the same period of the year. 



On the morning of the 14th July, which was exceptionally bright 

 and hot, I saw, in the meadows at Sils Maria, butterflies in such 

 extraordinary abundance that there seemed to be usually three or 

 four, and never less than one, on every flower-head, whilst others 

 were settled on the path and on the leaves of the grass. The greater 

 number were Fritillaries, but various Blues, a Large Copper, 

 Skippers, and others, were scarcely less abundant. As to the Fritil- 

 laries (of which there were certainby several species), they were so 

 numerous that, from one large plant of Phyteuma spicata, the flowers 

 of which were thickly covered with them, I took, with a single sweep 

 of the net, no fewer than thirty-three individuals ! I hesitate to 

 make the statement, but the fact is definitely recorded in my diary 

 under the date in question and I have still a very clear recollection 

 of the incident. 



The observation I wish to record is that the Fritillaries showed a 

 verv marked preference for the flowers of Hieracium aurantiacum. 

 1 noticed this particularly, because I was engaged at the time making 

 systematic observations on the " constancy " of insects when visiting 

 flowers (see Journ. Linn. Soc, Zool. xvii. pp. 186-194 (1884); also 

 Entomologist, xvi. pp. 145-150, 177-181 (1883), and xvii. pp. 81-86 

 (1884)). The preference shown by the Fritillaries for the flowers 

 of the Hieracium was too obvious to be overlooked. Many times 1 

 intentionally disturbed a Fritillary which had just alighted on a 

 flower of this plant, and almost invariably, after a short flight, it 

 alighted on another flower of the same species. This occurred regu- 

 larly, even though I disturbed the same insect five, six, seven, or 

 eight times. The preference Avas, indeed, beyond dispute. I had 

 first noticed it, in meadows at Pontresina, on the 4th of the month, 

 and again elsewhere on later days ; but I never observed it to the 

 same extent as on the date in question — which was due, doubtless, 

 to the exceptionally hot weather on that day. 



There can be no question, I think, that we have here a clear case 

 of protective colouration ; for the bright brownish-red or rich orange- 

 brown of the flowers of the particular form of Hieracium aurantia- 

 cum in question agrees so closely with the general golden-brown 



