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THE LIFE-HISTORY OF LORANTHUS EXOCARP1 Behr. 



By C. C. Brittlebank. 



(Communicated by A. G. Hamilton.) 



(Plates xv. -xx.) 



From the standpoint of economic forestry alone, owing to the 

 rapid spread and great damage caused by the Lorantbs in parts 

 of Victoria, the life-history of these plants is worthy of study. 

 Twenty years ago these parasites were very scarce in this, the 

 Myrniong district; but at the present time there is scarcely a 

 tree free from them; some indeed support several dozen separate 

 plants. 



For several reasons, some of which are given below, I look 

 upon the Loranths as recent introductions from the north into 

 the south-eastern portion of Australia. They probably came 

 south after the last cold period to which Victoria was subjected. 

 This view is strengthened by there being no record of Loranthus 

 in Tasmania. A bird, the Swallow Dicseum, which feeds upon 

 the fleshy portion of the fruit of these parasites is not found to 

 the south of Bass Strait. The seeds are fairly large and heavy, 

 and quite incapable of being borne by wind to any considerable 

 distance. We must therefore suppose that the parasites reached 

 the southern shores of Victoria after Tasmania was cut off from 

 the mainland. 



The various host-plants on which L. Exocarpi has been 

 observed in this district are Acacia sp., A. decurrens, A. dealbata, 

 A. implexa, A. melanoxylon, A, pycnantha, Bursaria spinosa, 

 Casuarina sp., C. quadrivalvis, Exocarpus cicpressiformis, Hymen 

 anthera Banksii, Native Hazel, Loranthus pendidus, Prunus 

 cerasus, and P. domestica. 



