S THE LORANTHACEAE OP AUSTRALIA^ 1., 



Seeds and Germination. 



The seeds of all the Australian Loranthus are surrounded by visein, enclosed 

 in a thin membranous sac, strengthened by 4 to 6 longitudinal flaccid appen- 

 dages, rising from the somewhat spongy base, and extending 2 to 4 mm. beyond 

 the seed. The visein sac varies in leng-th according to the size of the fruit. The 

 spongy base is also very variable; in some species it is a mere speck, in others 

 it is 5 mm. long, and about as broad. When the \'iscin is exposed to the air it 

 hardens somewhat, and changes in appearance, until it appears like gum or 

 resin. In Phrygilanthus celastroides and P. eucalypti folvus, it becomes quite 

 gTimmy. If soaked in formalin mixture it turns white, like hard mutton fat, 

 and can be separated from the seed without difficulty, but if placed in the same 

 mixture fresh from the epicarp, it remains soft and gelatinous. 



James Drummond (Hooker's Jour. Bot., v., 1853, p. 406) contributed the 

 following interesting notes on the seeds of a Western Australian Loranthus:— 

 "Some months ago, when I was dissolving some Acacia gum, which had been for 

 three-quarters of a year in my possession, I noticed that it contained seeds of 

 the beautiful Loranthus which grows on our Acacia. They seemed so fresh 

 that I placed them on the bark of a tree in the neighbourhood, where they 

 quickly germinated." 



The seeds of the Loranthus appear to need a fair amount of moisture to 

 ensure successful germination, and consequently the humid conditions prevailing 

 during portion of the summer are more favourable than the hot dry periods for 

 the successful development of the young seedlings. 



I have repeatedly noticed that on gennination the hypocotyl does not favour 

 a strong light, particularly the light from the side. In all the experiments 

 carried out by me on • the various species, the hypocotyl turned away from 

 the light; even when the hypocotyl was so placed that if it grew 

 forward it would come in contact with the host, instead it turned away. 

 Experiments conducted against a window subjected to strong sunlight are not 

 altogether favourable for the successful development of the young plants, for 

 they rarely grow beyond the attachment stage. In the natural surroundings the 

 light is often more uniform and the humidity more favourable than that of a 

 closed room, hence the young seedlings possess greater vitality, and readily adapt 

 themselves with vigour to the host, if it be a favourable one. 



On examining some ripe fruits of L. miraculosvs var. (b), I noticed that the 

 seed had already germinated, but the suctoral disc was unable to penetrate the 

 thick epicarp, and therefore was compelled to turn down towards the base of the 

 seed in some, while in others, the hypocotyl was spirally twisted and, when re- 

 leased, was too far gone to recover, having exhausted the supply of food from 

 the endosperm. 



In nearly all eases when germination takes place the hypocotj'l and embryonic 

 cotyledons show strong traces of chlorophyll, either a green or purple pigment. 

 In some seeds that contain but little albumen the embryo is quite green before 

 the fi-nit is fully ripe and, therefore, the irritability set up by germination can- 

 not altogether be a factor in the assimilation of chlorophyll within the embryo. 



The first pair of leaves that make their appearance in the germinating seed 

 of most species are not truly the cotyledons but the primary leaves. They are 

 sometimes i-udimentary, acicular, linear, spathulate, oblong, lanceolate and elliptic 

 in form, besides developing to a considerable thickness; they remain for a period 

 of a few months to four years on the young plants before they fall off. In such 

 species as P. celastroides and P. eucahjptifoKus they are markedly large for the 



