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HARD WI CKE ' S S CIE N CE- G OS SIP. 



BOTANY. 



Apospory in Ferns. — An important advance has 

 lately been made in the knowledge of the life-history 

 of ferns, and communications on the subject from 

 Mr. Charles T. Druery and Mr. F. O. Bower, may 

 be found in the "Journal of the Linnean Society." 

 In the place of the soii on Athyrium Filix-fccmina, 

 var. clarissima, a plant of which was originally 

 obtained wild in Devon, Mr. Druery found little 

 flask-shaped or pear-shaped bodies situated within an 

 undoubted indusium, but at this stage no spores or 

 spore-cases could be detected. On pinnre of the fern 

 being imbedded in soil under suitable conditions, 

 these bulbilloid [bodies began to develop, and in less 

 than three months decided prothalloid forms were 

 produced, on which archegonia and an antheridium 

 were afterwards found. Small fronds at length 

 projected from the bifurcation of the prothallus. 

 Mr. Druery considers that they had evidently 

 developed from the archegonia by the ordinary 

 method, though the prothalli themselves had sprung 

 from something very different from spores. Mr. 

 Bower confirms Mr. Druery's results and also 

 mentions the case of Polystichum augu/are, var. 

 pulcherrimum, in which there are undoubted pro- 

 thalloid bodies formed by purely vegetative growths 

 from the tips of the pinnules, and without any con- 

 nection with sori, sporangia, or spores, and which 

 bear antheridia and archegonia. The discovery of 

 this was due to Mr. G. B. Wollaston. The ordinary 

 series of conditions is thus even further broken in 

 upon in the case of the Polystichum than in that of 

 the Athyrium, since in the cycle of the former there 

 is nothing in the place of the bulbilloid growths of 

 the Athyrium or of the normal sporangium. The 

 antheridia and archegonia of the Polystichum were 

 not found to be open while the prothalloid 

 structures were on the leaves, the cause assigned as 

 probable being the want of the necessary moisture. 



Diatoms and Bladderwort. — Mr. Henry 

 Taylor has forwarded a slide containing a bladder of 

 Utricularia upon or within which are to be seen 

 numerous frustules of diatoms, upon the decomposing 

 endochrome of which he thinks the plant may have 

 fed. He says that Mr. Darwin, who does not in his 

 work on Carnivorous Plants mention Diatomacese 

 being found in the bladders of any of the species, 

 "appears to think the taking in of food by the 

 bladders is not owing to any voluntary act on 

 their part, but that the different things found in 

 them have merely forced their way in ; but as many 

 of these diatoms are stipitate and attached forms, 

 having no power of locomotion, like the free frustules, 

 this looks very much like their being seized by the 

 antennae round the valve of the bladder and conveyed 

 or swallowed in. I may add that the specimen I 



examined is a dried one, which has been in my 

 possession, in that state, for at least twenty years — 

 therefore not in a very good condition for examination. 

 I am very anxious to obtain some in a fresh state, and 

 should be much obliged if any one will inform me of 

 a locality (near London) where it can be found.' 1 

 Mr. Taylor is not however certain whether the 

 diatoms are inside or outside the bladder, and even 

 if they be inside it still remains to be shewn that 

 they are utilised as food by the plant. Mr. F. Kitton, 

 F.R.M.S., has been kind enough to give his opinion 

 as to the position of the diatoms. Speaking about 

 the one slide forwarded, Mr. Kitton says: "The 

 diatoms are, I have no doubt, upon the bladder of the 

 Utricularia as the species are all parasitic (and no 

 doubt occurred on other parts of the plant), they could 

 not have been injected by the bladder as it possesses 

 no prehensile organs which would be necessary to 

 detach the diatoms from their stipes. . . . The follow- 

 ing are the species attached : Gomphoncma con- 

 strictum, Synedra capitata, Cocconema lanccolatum , 

 Diatomevuigare." The point is one however of some 

 interest, and it would be well if it were thoroughly 

 cleared up by means of the examination of fresh 

 specimens. 



GEOLOGY, &C. 



Carboniferous Flora. — In "The Annals and 

 Magazine of Natural History " for June, is a paper 

 by Mr. Robert Kidston, F.G.S., on some "Fossil 

 Plants from the Lanarkshire Coalfield." Mr. Kidston 

 is intending to work out the distribution of the 

 carboniferous flora, and will be glad if others who 

 possess specimens of carboniferous fossil plants will 

 allow him to examine them, and he, on his part, 

 will be glad to help students in this department. 



Dr. Callaway on Comparative Lithology. 

 — In a paper entitled "A Plea for Comparative 

 Lithology," contributed to the " Geological Maga- 

 zine " for June, Dr. Callaway, F.G.S., returns to the 

 question of mineral composition, and refers to a 

 paper read by him before the Geological Society, of 

 which a notice may be found on p. 117 of this 

 volume. He thinks that lithological resemblances 

 may be pointed out without necessarily correlating 

 the rocks thus shewn to be similar, while, on the 

 other hand, we need not always wait for ocular 

 demonstration before venturing to correlate. Though 

 the mineral composition of Post-Archsean strata may 

 not be of much value, nor serve, even if fossils were 

 absent, to establish a law of correlation, the same is 

 not the case with the Archaean rocks, and Dr. 

 Callaway believes there are grounds for the " conclu- 

 sions that, in the British area at least, crystalline 

 schists have not been manufactured on a large scale 

 in Post-Archrean times, and that, amongst the 



