276 Transactions of the [Sess. 



synonyms were given for it, such as TJredo nivalis (Bauer), Pal- 

 mella nivalis (Hooker), Protococcus Tcermesinus (Agardh), Sphcerella 

 nivalis (Sommerfeld), Lepraria Jcermesina (Wrangel), &c. Fantastic 

 explanations of the origin of these bodies were soon forthcoming. 

 By some the sun was supposed to contribute a peculiar life-giving 

 principle to the snow ; while by others the red bodies were re- 

 garded as foreign, and as being, in the first instance, collected 

 on its surface by the wind, and then further aggregated by the 

 melting of the snow. That each of these bodies could develop 

 further on the surface of the snow was regarded as very pro- 

 bable. By others, again, the '' so schwer zu erweisende Generatio 

 primitiva " was maintained ; while by yet others their fungoid 

 rather than their algoid nature was regarded as the more probable. 



The account thus given, from a naturalist's point of view, was 

 combated in 1819 by Cladni, who ascribed the redness of snow to 

 the presence of meteoric dust, and who deprecated the manner in 

 which this had been overlooked by Bauer and others. Cladni even 

 believed that in red snow from South Switzerland he detected pyr- 

 oxene, or augite-like substances. 



The orange-coloured snow which Scoresby had seen in the neigh- 

 bourhood of Greenland was regarded by him as not unlikely of 

 specific difference from the red snow noticed by Captain Eoss. In 

 the green sea-water, red spots which seemed to correspond with ap- 

 pearances of a similar kind in various places inshore were seen. 

 These spots were believed to be caused by the presence of very 

 many small acephalee — which, however, seemed to be devoid of 

 swimmina: organs — and to these the redness of the snow was 

 ascribed ;^ but no further investigations were made in connection 

 with them. 



In the province of Padua, in Italy, the presence of blood-coloured 

 spots excited much curiosity about the year 1824. Sette investi- 

 gated the cause of these, and found it to be the presence of a red 

 filamentous fungus, which he named Zoogalactina inehrosUj and re- 

 ferred to as a hitherto unknown genus. Only a year later De Can- 

 dolle made further observations on the red colour of a lake in South 

 Switzerland, the unusual hue being well known to the fishermen in 

 that neighbourhood. Engelhardt, Haller, and others had also ob- 

 served the appearance, and arrangements had been made to pro- 

 secute a chemical analysis. De Candolle found the colour to be 

 due to the presence of a yet undescribed species of Oscillatoria, 

 which was described as 0. ruhescens ; while the chemical analysis 

 revealed the presence, among other things, of red and green resin- 

 ous materials, mucilage, an alkali, and iron-oxide. With respect 

 to the Oscillatorise, an interesting observation was made, namely, 

 that during sunshine they rose to the surface of the water, while 



1 'Edin. New Phil. Jour.,' 1828; 'Ann. d. Sci. Nat.,' 1829, p. 218. 



