HARDWICKE'S SCIENCE-GOSSIP. 



163 



not been disturbed, and not only not disturbed, but 

 subjected to such intense heat from fire, that one 

 would suppose, that any life, some inches below 

 the surface, must become extinct. It is the custom 

 for farmers to take up small selections of land, con- 

 sisting partly of lightly-timbered forest land, and 

 partly of " scrub land," which any Australian will 

 know to mean land thickly covered with gigantic 

 trees, between which grow up numerous smaller 

 trees, under which again is a luxurious growth of 

 underwood, the whole bouud together with a great 

 variety of creepers, varying from the size of a 

 small cane to the thickness of a man's body, which 

 grow up the largest trees and down again to the 

 ground, forming altogether so dense a mass that it 

 is impossible to enter it an arm's length without 

 cutting one's way. From the dropping of the 

 leaves of many centuries the soil becomes very 

 rich, and the farmer will prefer to go to the trouble 

 of cutting down this jungle, and cultivating the 

 rich land, to cultivating the comparatively open 

 forest land, which is very inferior in quality. When 

 the trees are all felled the branches lie over the 

 entire surface of the ground in a mass several feet 

 high, which, when well dried by the heat of the sun, 

 is fired on the windward side : the fire rages during 

 a whole day, and on some parts considerably longer, 

 till all the smaller wood is entirely consumed, and 

 only the stumps and the largest trunks of the trees 

 remain blackened and charred. As soon as the 

 ground has sufficiently cooled, the farmer goes 

 amongst the logs, and without any breaking up 

 of the soil, which is quite loose and friable, 

 makes holes at short distances with a stick called 

 " a dibber," and drops into each hole three or four 

 grains of maize, which, after the first shower of 

 rain, immediately spring up; but also from the 

 mass of charcoal and ashes there springs up a large 

 crop of wild flowers and plants, of which we do not 

 know the names, but amongst which we find 

 very abundant the tomato bush, which is in a 

 few weeks covered with the beautiful rich ripe 

 red fruit of the plain round species, which may be 

 gathered by the hundredweight; also the well-known 

 Cape gooseberry-bush, which bears a large crop of 

 its sweet fruit, resembling a cherry without a 

 stone, and each berry enveloped in a neat little 

 husk of something very like whitey-brown paper. 

 Besides these a very sweet-scented white lily, about 

 a foot high, grows in great profusion ; with a great 

 number of other plants, and very pretty flowers, 

 which grow so freely that we have to cut them 

 down, or they would interfere with the growth 

 of the maize. Now, previously to burning the scrub, 

 there had not been the least appearance of any of these 

 plants here or for many miles around ; they continue 

 to grow, aud do not, as your former correspondent 

 observes in the case he mentions, become extinct ; 

 but, on the contrary, they increase year by year, 



where we do not destroy them ; nor do we ever 

 find a similar sudden appearance at any spot which 

 has not been subjected to the fire. This is a fact 

 of every-day occurrence in the bush. I might also 

 mention that the open forest laud is generally 

 covered with grass, which grows in little separate 

 plants or tufts ; but if from burning off timber we 

 have frequently had a fire at one place, we in- 

 variably find that the tuft grass does not reappear, 

 its place being speedily taken by the couch grass.— 

 A. J. A., Brisbane. 



Pleohorphism.— I cannot see the connection, 

 which Mr. Duffy seems to indicate the existence 

 of, between the facts that certain chemical sub- 

 stances alter in their properties when under 

 different conditions without losing their chemical 

 identity; that one stage in the reproduction of 

 lowly-organised cellular plants resembles organisms 

 considered to be lowly-organised animals ; that 

 fungi not only produce buds, but also sexual 

 organs ; and that there are two distinct varieties 

 of the primrose which cross freely. To commit 

 oneself to the parallelism of .the two first cases, 

 would be to countenance all the fallacies of 

 Heterogenesis. If the existence of a vegetative 

 and a reproductive system be " Pleomorphism," 

 then all organic beings except the Protista are 

 so. The two varieties of the primrose occur not 

 only not on the same blossom under different 

 conditions, which would be allotropic, but not 

 even on the same plant. The dimorphism is 

 dieecious. Does Mr. Duffy merely mean to point 

 out that there are both resemblances and differences 

 between the " three kingdoms," between varieties 

 of one species, individuals of one variety, and even 

 the characters of individuals under different condi- 

 tions ?— &. S. Boulger. 



GEOLOGY. 



Living Ceratodus. — Professor Gervais an- 

 nounces that he has received from the Erench 

 Consul at Melbourne, an intimation of a new form 

 of fish allied to the Ceratodus, in the river Eitzroy. 

 It has all the characters of Ceratodus Fosteri, but 

 differs from it sufficiently to be regarded as a 

 distinct genus, to which the name of Neoceratodus 

 Blanchardi has been given. 



Thb Old Glaciers oe the Northern Slope 

 of the Swiss Alps.— This was the title of a paper 

 recently read before the Geological Society of 

 London, by Professor Alphonse Eavre. The 

 author illustrated his remarks by a map on a scale 

 f xs&fst, showing the space occupied by the old 

 Swiss glaciers at the time of their greatest extension, 

 and founded in part upon evidence obtained since 

 1867, when he, in conjunction with Prof. Studer 



