BIOLOGY 



Life in Salt Lakes 



Green Lake is very saline. We do not yet know how 

 much saline matter the water contains when the lake is 

 entirely melted and mixed up by wind. The fluid obtained 

 from under the ice in winter is a very dense and strong- 

 smelling brine. There is abundance of life in this lake, 

 but the number of kinds is much less than in the other 

 lakes. Only two out of the twelve species of rotifers 

 known at Cape Royds live in it. One of these {callidina 

 constricta) is not very plentiful; the other {adineta 

 grandis) is extremely so. This animal, while developing 

 the power of enduring cold, has at the same time become 

 accustomed to living in salt water. Though they were 

 not killed by the Green Lake brine, which is so much Salter 

 than the sea-water, none of these rotifers have been found 

 in the sea. t 



W ATER-BEARS IN ICE 



Water-bears were found to hve while frozen in ice 

 just as well as the rotifers did. It is an interesting fact 

 that the only abundant species at Cape Royds is an Arctic 

 species (macrobiotus arcticus) which was only previously 

 known in Spitzbergen and Franz Josef Land, and which 

 has not yet been detected in the various collections made 

 on the other side of the Antarctic by Bruce's and Nor- 

 denskj old's expeditions. 



Distribution of Rotifers, &c. 



Most of the rotifers and other animals were found 

 generally distributed in all the lakes visited. These cov- 

 ered a very limited area, the most distant being no more 

 than thirty miles apart. The nature of the microscopic 

 fauna of other parts of the Antarctic is scarcely knoTO. 

 Some of the Cape Royds lakes are richer than others, 

 and the saline lakes are poorer, but the general distribu- 



243 



