886 SUilJIAUY OF CURRENT RESEARCHES RELATING TO 



that Eophyton, Bilohites, and other similar structures are of vegetable 

 origin. The absence of carbon in these remains, a fact greatly relied 

 on by Nathorstj is explained by Saporta on the following hypothesis: — 

 A plant-stem of sufficient substance to resist pressure, but destined 

 in the long run to decompose, would, if resting on the sea-buttom, 

 become covered with sand or silt, if such deposit were taking place. 

 As the weight increased above it, its under surface would become 

 pressed into the bed upon which it chanced to be resting. As it 

 decomposed, inflated sediment would replace the organic matter, 

 until finally, the decomposition being complete, the sediment from 

 above entirely fills in the space, leaving on the under surface a re- 

 production in semi-relief of the decayed organism, while the upj)er 

 part is merged in the sand. 



There would, on this view, be no doubt about the algal nature of 

 the Chondrites of the tertiaries, cretaceous, and lias, the Aledoruridce, 

 an extinct group existing from the silurian into the tertiaries, and 

 their extinct ally Glossophycus ; while there is somewhat more doubt 

 about the gigantic liassic Laminarice with reticulated structure. The 

 Eophyton of the lower cambrian is almost proved, by its occasionally 

 cylindrical form and interlacing fragments, and by its being wholly 

 confined to this most ancient formation, to be something more than 

 mere scratches upon ooze ; though the evidence does not prove 

 conclusively that it is a plant. 



A. G. Nathorst in reply * says that Saporta has occupied himself 

 with defending stone algfe, and has somewhat exaggerated the author's 

 views, the real fact being that he has only questioned the vegetable 

 nature of the objects classed by Schimper in Zittel's ' Handbuch der 

 Palaontologie ' as AlgcB incertce sedis. He is about to combat the 

 views of Saporta more fully in a special work. 



Occurrence of Aphanizomenon Flos-aquae in Ice.f — P. Magnus 

 observed on ice 13 cm. thick an upper green zone about 5 cm. thick 

 composed of this alga. The filaments vrere vertical to the surface of the 

 ice, in consequence of the ascent of air-bubbles in the freezing water. 

 When cultivated the bundles became decomposed into their separate 

 filaments. The filaments had neither heterocysts nor spores, but 

 otherwise showed a comj^lete agreement with typical sj)ecimens of the 

 alga. The locality was not one in which Aphanizomenon had been 

 previously observed, but only Pohjcystis, Clathrocystis, and Anabcena ; 

 it appears to thrive in a colder temperature than these algse. 



Ovulites, a Group of Dichotomous Siphonese.J — M. Munier- 

 Chalmas argues that the Ovulites, hitherto jjlaced by palaeontologists 

 among the monothalamic foraminifera, are in reality Siphonaceous 

 algfe nearly allied to Coralliodendron, Espera, and Mhipocepjhalus, 

 The fossil Ovulites can in fact hardly be distinguished from the 

 recent Coralliodendron of our warmer seas. In both we find the 

 dichotomous branches which compose the frond inserted on a stipes 



* Nature, xxviii. (1883) pp. 52-3. 



t Ber. Deutsch. Bot. Gesellsch., i. (1883) pp. 129-32. 



J Bull. Soc. Ge'ol. Fiancf, vii. p. 6G1. See Rev. Sci. Nat., xi. (1883) p. 463. 



