ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 267 



Ascension and near Cape Verde, which seems to prove that the water 

 containing " Sti/li-Planlrton " moves as an under-current below the water 

 of the tropical Atlantic that contains " Desmo-Planlrton." Of forms 

 probably belonging to the Antarctic " Tricho-Plankton" Cleve found 25 

 in all, of which 48 p.c. also occur in the Arctic regions. These figures 

 eeem to the author to afford very strong evidence of the correctness of 

 Chun's theory that there is a connection between the Arctic and Ant- 

 arctic seas by means of under-currents. 



Red Sea Plankton. * — P. T. Cleve gives a list of 99 plankton 

 organisms from the Red Sea. Of the Copepods 8 p.c. and of the Diatoms 

 3 p.c. have not hitherto been found outside of this area, but this is 

 probably due to insufficient research. Almost all the Copepods (92 p.c.) 

 occur also in the Indo-Pacific region, 38 p.c. also in the tropical Atlantic ; 

 of the Diatoms 22 p.c. only occur in the tropical Atlantic, but 64 p.c. in 

 the temperate and northern Atlantic. There can scarcely be any doubt 

 that the water which spreads in the spring north of the Azores and 

 during the summer moves towards Iceland and the Faroe Channel, is 

 derived from the southern Atlantic, in part from the Antarctic Ocean. 

 The same is probably the case, to some extent at least, with the water 

 that enters the Red Sea. Thus we find there Thalassiothrix longissima, 

 an Arctic and Antarctic species, which can hardly live permanently in 

 water of so high a salinity and temperature as that of the Red Sea. 



Fauna of Hot Springs. - ! - — Dr. R. Issel has made a useful study of 

 the animal life of hot springs and the like in Italy. So far his com- 

 munication is only a series of lists, with the physical data of the waters, 

 but it shows that the fauna is larger than might have been expected. 



Fauna of Mountain Torrents.} — Prof. F. Zschokke points out the 

 peculiar conditions of life in the Swiss glacial torrents, and the way in 

 which the animals are adapted to their special surroundings. The locality 

 is possible only for such forms as can tolerate low temperature, can 

 withstand the force of the currents, and are carnivorous to a great extent, 

 at least in habit, for plants are few. The waters of such streams are 

 abundantly oxygenated, and all the inhabitants appear to be sensitive to 

 any impurity in the water. The fauna is singularly compact, including 

 Planaria alpina, a series of Hydrachnids ( Sperchon, Feltria, Thyas, 

 Partnunia and Panisus), two water-snails (Lyvmsea truncatula and L. 

 jperegra), and a large number of insect larvae, especially Ephemeridae, 

 Perlidaa, Phryganidae, and some Diptera (Simulia, Liponeura, Chirono- 

 mus). In the insects especially the variety in the organs of fixation is 

 remarkable. 



I Coloration of Marine Animals. § — Prof. W. C. Mcintosh surveys 

 the chief groups of marine animals in reference to their colour pheno- 

 mena, and concludes that while certain cases lend some support to such 

 theories as those involved in the terms protective resemblance, warning 

 coloration, and so on, there are nevertheless many other cases where 

 the application of such explanations is a matter of great difficulty. 



* Ofversigt. k. Vetensk. Akad. Forhandl., 1900, pp. 1025-38 (3 figs.), 

 t Atti Accad. Sci. Torino, xxxvi. (1901) pp. 53-74. 

 t Arch. Sci. Phvs. et Nat., x. (1900) pp.*557-60. 

 § Ann. Mag. Nat. Hist., vii. (1901) pp. 221-40. 



