BY W. F. BLAKELY. 15 



some eases the plants are the result of seed germinating upon the roots, having 

 fallen from the parent plant or been deposited by birds or other agencies. If a 

 large plant be examined in the fruiting season when the fruits are ripe, a num- 

 ber of young seedling parasites will be seen adhering to the branches, roots, 

 and even leaves of the parent plant. So that many of the sucker-like growths 

 observed on the roots are due to reproduction from its own seed, and in this 

 manner large clumps are often formed upon the roots and branches of the host, 

 thus illustrating another form of parasitism — "self or secondary." 



It is interesting to note that when this form of parasitism takes place tlie 

 union of the two parasites is scarcely distinguishable, and would be passed over 

 in a great many cases as ordinai'y branches.* There are occasional exception* 

 when the union gives rise to a ball-like swelling, and when this is the case, the 

 plants are much larger and more vigorous than when no union is perceptible. 

 Another point of interest is the deterioration in the size of the parasite when 

 living upon its parent. The result is a diminution chiefly in the shortness of its 

 branches and leaves, or in other words, smaller plants are produced, after a year 

 or two. Adventitious roots act in the assimilation of moisture for the plant. 

 As will be noticed when attached to a dead branch, their haustoria push their 

 way beneath the dead bark in quest of food or moisture; they do not enter 

 very far into the dead cambium, bvxt adhere fii-mly to it. When by chance or 

 accident they become attached to the dead wood, the haustoria or root suckers 

 are more numerous, and are sometimes closely followed by each other in a con- 

 tinual line beneath the main runner, and resemble a number of grubs in out- 

 line. . During favourable weather, that is, when the weather is warm and there 

 is a bounteous rainfall, the growth of these roots upon the dead branches is 

 very marked, and is indicative of the part played by them in providing moisture 

 for the plant. It may also be surmised that when the haustoria feed upon dead 

 wood or bark, a fair amount of liquid food is absorbed by them which must 

 naturally benefit the plant. It is well known that decaying vegetable matter 

 contains plant food, and it is quite reasonable to assume that in carrying out 

 their functions these adventitious roots, with the aid uf their haustoria, convey 

 a considerable amount of nutriment to the plant, and are therefore of much 

 value to it, not only as a means of assisting the plant to adhere firmly to the 

 host, but also as an agent of assimilation. 



The following species jaossess adventitious roots : — Phrygilanthus Bidioillii^ 

 P. myrtifolia, P. eucalyptifolius, P. celaetroides, Loramthus vitelUnus, L. clictyo- 

 phlehus, L. odontocalyx, L. alyxif alius, L. hiangulatus. 



The Union or Attachment. 



In the Australian Loranthaceae there are two distinct forms of union or 

 attachment with the host, namely, ball-like and fusiform. 



The first is brought about in two ways: (1) Wlien the wood of the parasite 

 exjaands into a ball-like excrescence over the wood of the host, and (2) When 

 the penetration of the radicle causes the wood of the host to form a ball-like 

 growth around the point of attachment of the parasite. Both no doubt are 

 the result of a straight or single puncture of the radicle. To the first, I h^ve 



* I find that Mr. J. J. Fletcher has made the same discovery in reference to 

 this form of parasitism, and has placed it on record in these Proceedings (xxx.. 

 1905 (1906), 489). 



